4. Systematic code examples: a guided tour of Transcrypt¶
One ready-to-run code example is worth more than ten lengthy descriptions. The autotest and demo suite, that is part of the distribution, is a collection of sourcecode fragments called testlets. These testlets are used for automated regression testing of Transcrypt against CPython. Since they systematically cover all language constructs, they are also very effective as a learning tool. The testlets are arranged alphabetically by subject.
import org.transcrypt.autotester
import arguments
import attribs_by_name
import builtin_super
import byte_arrays
import callable_test
import classes
import complex_numbers
import conditional_expressions
import control_structures
# __pragma__ ('ifdef', '__py3.6__') # Needed because Transcrypt imports are compile time
if '__py3.6__' in __symbols__: # Needed because CPython doesn't understand pragma's
import dashed_numbers
# __pragma__ ('endif')
import data_structures
import decorators
import dict_comprehensions
import dictionaries
import div_issues
import div_pulls
import docstrings
import exceptions
import extended_slices
# __pragma__ ('ifdef', '__py3.6__') # Needed because Transcrypt imports are compile time
if '__py3.6__' in __symbols__: # Needed because CPython doesn't understand pragma's
import fstrings
# __pragma__ ('endif')
import general_functions
import globals_function
import indices_and_slices
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
import iterators_and_generators
# __pragma__ ('endif')
import lambda_functions
import list_comprehensions
import local_classes
import metaclasses
import method_and_class_decorators
import module_builtin
import module_cmath
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
import module_itertools
# __pragma__ ('endif')
import module_math
import modules
import nonlocals
import operator_overloading
import properties
import reprtest
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
import proxies
# __pragma__ ('endif')
import set_comprehensions
import simple_and_augmented_assignment
import truthyness
import tuple_assignment
autoTester = org.transcrypt.autotester.AutoTester ()
autoTester.run (arguments, 'arguments')
autoTester.run (attribs_by_name, 'attribs_by_name')
autoTester.run (builtin_super, 'builtin_super')
autoTester.run (byte_arrays, 'byte_arrays')
autoTester.run (callable_test, 'callable')
autoTester.run (classes, 'classes')
autoTester.run (complex_numbers, 'complex_numbers')
autoTester.run (conditional_expressions, 'conditional_expressions')
autoTester.run (control_structures, 'control_structures')
# __pragma__ ('ifdef', '__py3.6__')
if '__py3.6__' in __symbols__:
autoTester.run (dashed_numbers, 'dashed_numbers')
# __pragma__ ('endif')
autoTester.run (data_structures, 'data_structures')
autoTester.run (decorators, 'decorators')
autoTester.run (dict_comprehensions, 'dict_comprehensions')
autoTester.run (dictionaries, 'dictionaries')
autoTester.run (div_issues, 'div_issues')
autoTester.run (div_pulls, 'div_pulls')
autoTester.run (docstrings, 'docstrings')
autoTester.run (exceptions, 'exceptions')
autoTester.run (extended_slices, 'extended_slices')
# __pragma__ ('ifdef', '__py3.6__')
if '__py3.6__' in __symbols__:
autoTester.run (fstrings, 'fstrings')
# __pragma__ ('endif')
autoTester.run (globals_function, 'globals_function')
autoTester.run (general_functions, 'general_functions')
autoTester.run (indices_and_slices, 'indices_and_slices')
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
autoTester.run (iterators_and_generators, 'iterators_and_generators')
# __pragma__ ('endif')
autoTester.run (lambda_functions, 'lambda_functions')
autoTester.run (list_comprehensions, 'list_comprehensions')
autoTester.run (local_classes, 'local_classes')
autoTester.run (metaclasses, 'metaclasses')
autoTester.run (method_and_class_decorators, 'method_and_class_decorators')
autoTester.run (module_builtin, 'module_builtin')
autoTester.run (module_cmath, 'module_cmath')
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
autoTester.run (module_itertools, 'module_itertools')
# __pragma__ ('endif')
autoTester.run (module_math, 'module_math')
autoTester.run (modules, 'modules')
autoTester.run (nonlocals, 'nonlocals')
autoTester.run (operator_overloading, 'operator_overloading')
autoTester.run (properties, 'properties')
autoTester.run (reprtest, 'repr_str')
# __pragma__ ('ifdef', '__esv6__')
if '__esv6__' in __symbols__:
autoTester.run (proxies, 'proxies')
# __pragma__ ('endif')
autoTester.run (set_comprehensions, 'set_comprehensions')
autoTester.run (simple_and_augmented_assignment, 'simple_and_augmented_assignment')
autoTester.run (truthyness, 'truthyness')
autoTester.run (tuple_assignment, 'tuple_assignment')
autoTester.done ()
4.1. Arguments: **kwargs, *args, defaults, at call and def time, also for lambda's¶
from org.transcrypt.stubs.browser import __pragma__
__pragma__ ('kwargs')
class A:
def __init__ (self, x = 123, y = 456, *args, m, n = 456, **kwargs):
self.x = x
self.y = y
self.args = args
self.m = m
self.n = n
self.kwargs = kwargs
self.extra = 'hello'
def f (self, autoTester):
autoTester.check (self.x, self.y, self.args, self.m, self.n, self.kwargs, self.extra)
class B (A):
def __init__ (self, x, y = -1, *args, m = -2, n, **kwargs):
A.__init__ (self, y, x, *args, m = n, n = m, **kwargs)
class C:
__pragma__ ('nokwargs')
def tricky (self, *args):
return args
__pragma__ ('kwargs')
def run (autoTester):
def f (x, y = -1, *args, m = -2, n, **kwargs):
# BEGIN issue 203, kwargs turned into real dict
autoTester.check ('#203', kwargs.__class__.__name__)
autoTester.check ('#203', sorted (kwargs.keys ()))
# END issue 203
def f2 (x, y = -3, *args, m = -4, n, **kwargs):
autoTester.check (x, y, args, m, n, kwargs)
f2 (11, 22, 1010, 2020, m = 100100, n = 200200, p = 10001000, q = 20002000)
autoTester.check (x, y, args, m, n, kwargs)
f (1, 2, 10, 20, m = 100, n = 200, p = 1000, q = 2000)
b = B (3, 4, 30, 40, m = 300, n = 400, p = 3000, q = 4000)
b.f (autoTester)
def g (*args, **kwargs):
autoTester.check (args, kwargs)
g (*(1, 2, 3), **{'p': 'aP', 'q': 'aQ', 'r': 'anR'})
(lambda x, y = -1, *args, m = -2, n, **kwargs: autoTester.check (x, y, args, m, n, kwargs)) (1, 2, 8, 16, m = 128, n = 256.3, p = 1024.3, q = 2048.3)
autoTester.check (C () .tricky (* range (4)))
autoTester.check ('{}-{}'.format (1, 3, 5, 7, 9))
autoTester.check ('{}-{}'.format (* range (4)))
4.2. Attribute access by name: getattr, setattr, hasattr¶
class A:
def __init__ (self):
self.s = 'hello'
a = A ()
def run (autoTester):
autoTester.check (a.s, getattr (a, 's'))
setattr (a, 's', 'goodbye')
autoTester.check (a.s, getattr (a, 's'))
setattr (a, 't', 'exists')
autoTester.check (hasattr (a, 't'), a.t, getattr (a, 't'))
delattr (a, 't')
autoTester.check (hasattr (a, 't'))
4.3. Attribute proxies by name: __getattr__, __setattr__¶
from org.transcrypt.stubs.browser import __pragma__
def run (autoTester):
class CodedStore:
def __init__ (self):
try:
__pragma__ ('js', '{}', 'self ["__dict__"] = {}')
except:
pass
def __setattr__ (self, name, message):
self.__dict__ ['_' + name] = 'coded_' + message
def __getattr__ (self, name):
return 'decoded_' + self.__dict__ ['_' + name]
def peek (self, name):
return self.__dict__ ['_' + name]
s = CodedStore ()
s.john = 'brown'
s.mary = 'white'
autoTester.check (s.peek ('john'))
autoTester.check (s.peek ('mary'))
autoTester.check (s.john)
autoTester.check (s.mary)
'''
The code above produces the following output:
'coded_brown'
'coded_white'
'decoded_coded_brown'
'decoded_coded_white'
'''
class A:
def __init__ (self):
self.p = 1
self.q = 2
class B (A):
def __getattr__ (self, name):
return 'Faked {}'.format (name)
class C (A):
def __setattr__ (self, name, value):
autoTester.check ('Set faked {}'.format (name))
A.__setattr__ (self, name, value)
# Needed for CPython, inherited from class 'object'
# Transcrypt doesn't need it, if there's no __setattrib__ it will just use self [name] = value
class D (B, C):
pass
a = A ()
b = B ()
c = C ()
d = D ()
autoTester.check (a.p, a.q)
a.p = 3
autoTester.check (a.p, a.q)
autoTester.check (b.p, b.q, b.r, b.s)
b.p = 4
b.r = 5
autoTester.check (b.p, b.q, b.r, b.s)
autoTester.check (c.p, c.q)
c.p = 6
c.q = 7
autoTester.check (c.p, c.q)
autoTester.check (d.p, d.q, d.r, d.s)
d.p = 8
d.q = 9
d.r = 10
d.s = 11
autoTester.check (d.p, d.q, d.r, d.s)
4.4. Bytes and bytearrays: initial support¶
def run (autoTester):
b = b'bike'
s = bytes ('shop', 'utf8')
e = b''
bb = bytearray ([0, 1, 2, 3, 4])
bc = bytes ((5, 6, 7, 8, 9))
# __pragma__ ('opov')
bps = b + b'pump' + s
bps3 = 3 * bps + b'\0'
aBps3 = bps * 3 + b'\0'
l = [1, 2, 3] + [4, 5, 6]
# __pragma__ ('noopov')
def formatCheck (aBytes):
autoTester.check ([int (aByte) for aByte in aBytes])
formatCheck (b)
formatCheck (s)
formatCheck (e)
formatCheck (bb)
formatCheck (bc)
formatCheck (bps)
formatCheck (bps3)
formatCheck (aBps3)
# __pragma__ ('opov')
formatCheck (bb + bc)
formatCheck (bytearray ('ding', 'utf8') + b'dang' + bytes ('dong', 'utf8'))
# __pragma__ ('noopov')
formatCheck (l)
4.5. Callable or not: using the callable () built-in function¶
The callable (object) built-in function will tell you if something supports the () operator.
# Callable built-in method unit tests
from org.transcrypt.stubs.browser import __pragma__
def run(test):
"""
"""
def func(a,b):
return(a*b)
test.check( func(3,4) )
test.check( callable(func) )
for a in (True, False):
test.check( callable(a) )
a = 1
test.check( callable(a) )
a = 2.3
test.check( callable(a) )
a = "asdf"
test.check( callable(a) )
a = []
test.check( callable(a) )
a = [1,2,3,3]
test.check( callable(a) )
a = ["asdf", "qwer", "zxcv"]
test.check( callable(a) )
a = {"asdf" : 1, "qwer": 2}
test.check( callable(a) )
a = set([1,2])
test.check(callable(a))
__pragma__('opov')
class CallObj(object):
def __init__(self, r):
self._r = r
def __call__(self):
return(self._r)
test.check( callable(CallObj) )
obj = CallObj(2)
test.check(obj())
test.check( callable(obj) )
test.check( callable(obj._r) )
class NonCallObj(object):
def __init__(self, b):
self._b = b
def func(self):
return(self._b)
test.check( callable(NonCallObj) )
obj2 = NonCallObj(2)
test.check( callable(obj2) )
test.check( callable(obj2._b) )
test.check( callable(obj2.func) )
__pragma__('noopov')
class NonOpovNonCallObj(object):
"""
"""
def __init__(self, c):
self._c = c
def other(self, b):
return(self._c * b)
def _getC(self):
return(self._c)
def _setC(self, val):
self._c = val
C = property(_getC, _setC)
obj = NonOpovNonCallObj(4)
test.check( callable(obj) )
test.check( callable(obj.other) )
test.check( callable(obj._c) )
test.check( callable(obj.C) )
exc = Exception("asdf")
test.check( callable(exc) )
4.6. Classes: multiple inheritance and assignment of bound functions¶
def run (autoTester):
autoTester.check ('<br>General<br>')
class A:
p = 123
def __init__ (self, x):
self.x = x
autoTester.check (self.p)
def show (self, label):
autoTester.check ('A.show', label, self.x)
def show2 (self, label):
autoTester.check ('A.show2', label, self.x)
class B:
p, q = 456, 789
def __init__ (self, y):
autoTester.check ('In B constructor')
self.y = y
autoTester.check (self.p)
def show (self, label):
autoTester.check ('B.show', label, self.y)
class C (A, B):
def __init__ (self, x, y):
autoTester.check ('In C constructor')
A.__init__ (self, x)
B.__init__ (self, y)
def show (self, label):
A.show (self, label)
B.show (self, label)
autoTester.check ('C.show', label, self.x, self.y)
a = A (1001)
a.show ('america')
autoTester.check (A.p)
autoTester.check (a.p)
b = B (2002)
b.show ('russia')
autoTester.check (B.p)
autoTester.check (b.p)
autoTester.check (b.q)
autoTester.check (A.p)
autoTester.check (a.p)
c = C (3003, 4004)
c.show ('netherlands')
autoTester.check (C.p)
autoTester.check (c.p)
autoTester.check (c.q)
c.show2 ('amsterdam')
A.show2 (c, 'rotterdam')
show3 = c.show
show3 ('copy')
autoTester.check (hasattr (a, 'x'))
autoTester.check (hasattr (a, 'y'))
autoTester.check (hasattr (a, 'p'))
autoTester.check (hasattr (a, 'q'))
autoTester.check ('<br><br>Augmented isinstance<br>')
# Augmented meaning: compatible with native JavaScript types
simpleTypes = (dict, list, A, B, C, bool, str, float, int)
tupleTypes = ((dict, list), (bool, int), (bool, A), (C, B))
for i, types in enumerate ((simpleTypes, tupleTypes)):
for j, aType in enumerate (types):
for k, anObject in enumerate (({'a': 1}, [], a, C, c, C, b, True, 'a', 1, 1.2)):
autoTester.check (i, j, k, isinstance (anObject, aType))
if types == simpleTypes:
autoTester.check (i, j, k, isinstance (anObject, simpleTypes))
autoTester.check ('<br><br>Method resolution order<br>')
def mro (aClass, result = None):
''' Recursively assemble method resolution order from all base classes'''
last = 0
if result is None:
result = [aClass]
last = 1
for aBase in aClass.__bases__:
if not aBase in result and aBase != object:
result.append (aBase)
mro (aBase, result)
if last and object in aClass.__bases__:
aRoot.append (object)
return result
autoTester.check ([aClass.__name__ for aClass in mro (C)])
4.7. Complex numbers: Python's builtin complex datatype¶
from org.transcrypt.stubs.browser import __pragma__
def run (autoTester):
x = 567
y = -3
z = 5 * x + 2 * y
autoTester.check (x, y, z)
__pragma__ ('opov')
a = 234 + 3j
b = 4 - 5j
c = complex (-6, 7)
autoTester.check (a, b, c)
t = 6 * x - 3 * y + 7 # Just to check, faster with 'noopov'
autoTester.check (t)
d = 2 * a
e = x * b
f = z + d + e
g = a / b
h = a - b
i = x - c
j = a - x
k = b + y
autoTester.check (d, e, f, round (g.real, 2), round (g.imag, 2), h, i, j, k)
__pragma__ ('noopov')
4.8. Conditional expressions: simple and nested¶
def f (x, b):
return x * x if b else x + x
def run (autoTester):
bools = (False, True)
for a in bools:
for b in bools:
autoTester.check (f (10 if a else 100, b))
for p in bools:
for q in bools:
for r in bools:
autoTester.check ('a' if p else 'b' if q else 'c' if r else 'd')
a = ((('e' if p else 'f') if q else 'g') if r else 'h')
b = ('i' if p else ('j' if q else ('k' if r else 'l')))
c = 'm' if (p if q else r) else 'n'
d = 'o' if p < q <= r else 'p'
autoTester.check (a, b, c, d)
odd = [x if x % 2 else x + 1 for x in range (10)]
noDuplicates = set (odd)
autoTester.check (odd, noDuplicates)
4.9. Control structures: for...else, while...else, if...elif...else, break, continue¶
def run (autoTester):
for index in range (10):
autoTester.check (index)
for index in range (8, 16):
autoTester.check (index)
for index in range (8, 16, 2):
autoTester.check (index)
for index in range (10, 0, -1):
autoTester.check (index)
for index in range (16, 8, -2):
autoTester.check (index)
for animal in ('cat', 'dog', 'turtle', 'goldfish'):
autoTester.check (animal)
for index, square in enumerate ([x * x for x in range (10) if x % 2]):
for y in (1, 2, 3):
for z in (10, 20, 30):
autoTester.check (square + y, z )
vehicles = ['bike', 'train', 'boat', 'car', 'plane', 'bus']
for doBreak in (False, True):
for doContinue in (False, True):
for index in range (10):
for index2 in range (0, 100, 10):
if doBreak and index2 == 50:
autoTester.check ('break2')
break
if doContinue and index2 == 50:
autoTester.check ('continue2')
continue
else:
autoTester.check ('noBreak2')
if doBreak and index == 5:
autoTester.check ('break')
break
if doContinue and index == 5:
autoTester.check ('continue')
continue
else:
autoTester.check ('noBreak')
index = 0
while index < len (vehicles) and vehicles [index] != 'bus':
autoTester.check (index, vehicles [index])
if doBreak and vehicles [index] == 'car':
autoTester.check ('breakWhile')
break
if doContinue and vehicles [index] == 'car':
autoTester.check ('continueWhile')
index += 1
continue
index += 1
else:
autoTester.check ('noBreakWhile')
for vehicle in vehicles:
if vehicle == 'bike':
autoTester.check ('netherlands')
elif vehicle == 'car':
autoTester.check ('america')
elif vehicle == 'boat':
autoTester.check ('oceania')
else:
autoTester.check ('anywhere')
4.10. Data structures: tuple, list, dict, set¶
def run (autoTester):
aList = [1, 2, 3, 'moon', 'stars']
autoTester.check (aList)
aList.insert (3, 'sun')
autoTester.check (aList)
autoTester.check (aList [2:4:1])
autoTester.check (aList [:])
autoTester.check (aList [2:])
autoTester.check (len (aList))
aList.append ('milkyway')
autoTester.check (aList)
aList.extend (['m1', 'm31'])
autoTester.check (aList)
anotherList = list (('a', 'b', 'c'))
autoTester.check (anotherList)
autoTester.check ('b' in anotherList)
autoTester.check ('d' in anotherList)
aDict = {1: 'plant', 'animal': 2}
autoTester.check (aDict)
autoTester.check (aDict [1], aDict ['animal'])
def p ():
return 3
q = 4
autoTester.check ({p (): 'three', q: 'four'})
aTuple = (1, 2, 3, 4, 5)
autoTester.check(aTuple)
autoTester.check (len (aTuple))
anotherTuple = (1,)
autoTester.check (anotherTuple)
aSet = {1, 2, 2, 3}
autoTester.check (aSet)
autoTester.check (len (aSet))
autoTester.check (2 in aSet)
autoTester.check (4 in aSet)
aSet.clear ()
autoTester.check (aSet)
anotherSet = set ((4, 5, 5, 6))
autoTester.check (anotherSet)
emptySet = set ()
autoTester.check (emptySet)
autoTester.check (len (emptySet))
aString = 'c_cis_d_dis_e_f_fis_g_gis_a_ais_b_c'
autoTester.check ('cis' in aString)
autoTester.check ('g' in aString)
autoTester.check ('bes' in aString)
autoTester.check ('z' in aString)
4.11. Decorators: function and class, with and without parameters¶
Transcrypt supports decorators on methods and classes. A decorator itself can be a function or an object with an overloaded __call__ operator. Parameterized decorator factories are also supported. All flavours of properties can be used directly or through decorator syntax. Extensive use of properties is demonstrated in the properties testlet.
from org.transcrypt.stubs.browser import __pragma__
def run (autoTester):
def repeat3 (bareFunc):
__pragma__ ('kwargs')
def innerFunc (*args, **kwargs):
autoTester.check ('BEGIN repeat3')
for i in range (3):
bareFunc (*args, **kwargs)
autoTester.check ('END repeat3')
__pragma__ ('nokwargs')
return innerFunc
def repeatN (n):
def repeat (bareFunc):
__pragma__ ('kwargs')
def innerFunc (*args, **kwargs):
autoTester.check ('BEGIN repeatN ({})'.format (n))
for i in range (n):
bareFunc (*args, **kwargs)
autoTester.check ('END repeatN ({})'.format (n))
__pragma__ ('nokwargs')
return innerFunc
return repeat
class Repeater:
def __init__ (self, n):
self.n = n
def __call__ (self, bareFunc):
__pragma__ ('kwargs')
def innerFunc (*args, **kwargs):
autoTester.check ('BEGIN repeat3')
for i in range (self.n):
bareFunc (*args, **kwargs)
autoTester.check ('END repeat3')
__pragma__ ('nokwargs')
return innerFunc
@repeatN (4)
@repeat3
def funcNoArg ():
autoTester.check ('spam')
funcNoArg ()
autoTester.check ()
__pragma__ ('kwargs')
@repeat3
@repeatN (2)
def funcArg (a):
autoTester.check ('eggs', a)
__pragma__ ('nokwargs')
funcArg (3)
autoTester.check ()
funcArg (a = 4)
autoTester.check ()
__pragma__ ('opov')
@Repeater (3)
def funcNoArg2 ():
autoTester.check ('toast')
__pragma__ ('noopov')
funcNoArg2 ()
autoTester.check ()
__pragma__ ('opov')
__pragma__ ('kwargs')
@Repeater (5)
def funcArg2 (a):
autoTester.check ('jam', a)
__pragma__ ('nokwargs')
__pragma__ ('noopov')
funcArg2 (3)
autoTester.check ()
funcArg2 (a = 4)
autoTester.check ()
def next (bareFunc):
def innerFunc (value):
return bareFunc (value + 1)
return innerFunc
@next
class Number:
def __init__ (self, value):
self.value = value
autoTester.check ('two', Number (1) .value)
class Test:
@classmethod
def f (cls, x, y):
autoTester.check (cls.__name__, x, y)
def g (self, x, y):
autoTester.check (self.__class__.__name__, x, y)
test = Test ()
test.f (1, 2)
test.g (3, 4)
4.12. Dict comprehensions¶
from org.transcrypt.stubs.browser import __pragma__
__pragma__ ('iconv') # Convert dict to key list without using keys () method
def run (autoTester):
original = {'Isaac': 'Newton', 'Albert': 'Einstein', 'Paul': 'Dirac'}
autoTester.check (original)
inverted = {original [key]: key for key in original}
autoTester.check (inverted)
4.13. Dictionaries: dict revisited¶
from org.transcrypt.stubs.browser import __pragma__
__pragma__ ('iconv')
# Dictionaries are translated to JavaScript objects,
# to achieve JSON-compatible syntax for JavaScript library object initialisation.
# Keys that may denote a number are interpreted as such in Transcrypt.
# All other keys are interpreted as strings.
def run (autoTester):
tel = {'guido': 4127, 'jack': 4098}
autoTester.check (len (tel))
tel ['sape'] = 4139
autoTester.check (tel)
autoTester.check (tel ['jack'])
del tel ['sape']
tel ['irv'] = 4127
autoTester.check (tel)
autoTester.check (sorted (list (tel.keys ())), False)
autoTester.check (sorted (tel.keys ()))
autoTester.check ('guido' in tel)
autoTester.check ('jack' not in tel)
autoTester.check (dict ([('guido', 4127), ('jack', 4098), ('sape', 4139)]))
autoTester.check (
autoTester.expectException( lambda: dict(1) )
)
autoTester.check (
autoTester.expectException( lambda: dict(134.34) )
)
autoTester.check (
autoTester.expectException( lambda: dict('asdf') )
)
autoTester.check (
autoTester.expectException( lambda: dict(['1234', 1]) )
)
autoTester.check( dict ([]))
autoTester.check (dict ({}))
autoTester.check (dict ({'asdf': 1, 'qwer': 2}) )
# check dict copy, Issue # 221
b = {'a' : 2.01, 'b': -3.3}
d = dict (b)
autoTester.check (d)
b = {'a' : 2, 'b': [1,2,3]}
d = dict (b)
autoTester.check (d)
b = {'a' : None, 'b': set([1,2,3])}
d = dict (b)
autoTester.check (d)
b = {'a' : {'c': 2}, 'b': (1,2)}
d = dict (b)
autoTester.check (d)
autoTester.check (d['a']['c'])
autoTester.check (d.get('a').get('c'))
autoTester.check (b.get('a').get('c'))
d['a']['c'] = 3
autoTester.check (d.get('a').get('c'))
autoTester.check (b.get('a').get('c'))
knights = {'robin': 'the brave', 'gallahad': 'the pure'}
for k, v in sorted (knights.items ()):
autoTester.check (k, v)
if 'gallahad' in knights:
autoTester.check ('gallahad is a knight')
for k in sorted (knights):
autoTester.check (k)
knight = {'rudolph': 'the righteous'}
for k in knight: # Autotest automatic conversion with one knight, since sort order of dict undefined
autoTester.check (k)
tel = {'guido': 123}
tel.update({'edsger': 42})
autoTester.check (tel.setdefault ('linus', 456))
autoTester.check (tel ['linus'])
autoTester.check (tel.setdefault ('guido', 789))
autoTester.check (tel.pop ('guido', 1))
autoTester.check (tel.pop ('guido', 1))
autoTester.check (tel.pop ('edsger', 2))
autoTester.check (tel.pop ('foo', 'bar'))
autoTester.check (tel.pop ('foo', None))
# Check compound keys (issue 281)
d = {}
d ['a'] = 3777
d [(1, 2)] = 4777
autoTester.check (d ['a'], d [(1, 2)])
__pragma__ ('opov')
d = {}
d ['a'] = 3777
d [(1, 2)] = 4777
autoTester.check (d ['a'], d [(1, 2)])
__pragma__ ('noopov')
# Check exceptions
knights = {'robin': 'the brave', 'gallahad': 'the pure'}
autoTester.check (
autoTester.expectException ( lambda: knights.pop("batman") )
)
autoTester.check (
autoTester.expectException ( lambda: knights.pop("batman", None) )
)
autoTester.check (
autoTester.expectException ( lambda: knights.pop("batman", "the gullible") )
)
4.14. Diverse issues¶
from org.transcrypt.stubs.browser import __pragma__, __new__, __envir__, __symbols__
from div_issues.issue55 import * # Names not exported from package's __init__.py, no output, only compilation check
from div_issues.issue387 import run387 # Support __module__ and __qualname__ for introspection (only __module__ done and
# __name__ set to '__main__ for main module'
def run (autoTester):
autoTester.check ('Issue 24') # Non keyword switch generates javascript SyntaxError
switch = False
autoTester.check (switch)
autoTester.check ('Issue 27') # Python list.index () not translated correctly
autoTester.check (['zero', 'one', 'two', 'three', 'four'] .index ('three'))
autoTester.check ('Issue 36') # Bug in compiling lambda default argument values
# Workaround for Python closures capturing variables rather than values
# An extra enclosing scope is created to remember the value of the variable
results = []
for i in range (10):
# results.append (lambda: i) # Works nowhere
# results.append (lambda j = i: j) # Works only in Python
results.append ((lambda j: lambda: j) (i)) # Works in Python and Transcrypt
autoTester.check ([result () for result in results])
autoTester.check ('Issue 37') # Python integer division not translated correctly
autoTester.check (15 // 7)
autoTester.check ('Issue 40') # Python parentheses dropped during translation
autoTester.check (65 / (5 * 2))
autoTester.check ('Issue 50') # Wrong answer with parentheses moved during translation
autoTester.check ((240 + 30 - 1) // 30 * 30)
autoTester.check ('Issue 51') # Wrong answer with set() compare
a = 1
b = 1
autoTester.check (a, b, {a, b} == {1, 2})
autoTester.check ('Issue 52') # Non keyword 'default' generates javascript SyntaxError
switch, case, default = 'switch', 'case', 'default'
autoTester.check (switch, case, default)
autoTester.check ('Issue 54') # Type dict missing clear(), setdefault()
aDict = {1: 11, 2: 22, 3: 33}
autoTester.check (aDict)
aDict.clear ()
autoTester.check (aDict)
autoTester.check ('Issue 60') # Python bool() not translated
three = 3
one = three & 1
seven = three | 4
eight = one << 3
four = eight >> 1
aTrue = bool (three & one)
aFalse = bool (three & four)
autoTester.check (3, three, 1, one, 7, seven, 8, eight, 4, four, True, aTrue, False, aFalse)
autoTester.check ('Issue 65') # Adding two lists with + not supported
__pragma__ ('opov')
aList = [4, 5, 6]
autoTester.check ([1, 2, 3,] + aList + [4, 5, 6])
autoTester.check (3 * [1, 2, 3])
autoTester.check ([1, 2, 3] * 3)
aString = 'Crocodile'
autoTester.check ('Tiger' + aString + 'Elephant')
autoTester.check (3 * aString)
autoTester.check (aString * 3)
__pragma__ ('noopov')
autoTester.check ('Issue 76') # Python //= not translated correctly
initially17 = 17
autoTester.check (initially17)
initially17 //= 2
autoTester.check (initially17)
initially17 //= 2
autoTester.check (initially17)
autoTester.check ('Issue 112') # When using -e6, iterating TypedArrays or other non-list Iterables doesn't work
try:
if __envir__.executor_name == __envir__.transpiler_name: # CPython doesn't know Int8Array
x = __new__ (Int8Array (2))
else:
x = [None, None]
x [0] = 3
x [1] = 2
for i in x:
autoTester.check (i)
# Since JavaScript 5 gives no exception for a loop over a non-iterable, following code must only be executed for JavaScript 6
# Since Transcrypt doesn't get to see all modules loaded by CPython, __ifdef__ cannot be made to do its thing for all modules in an efficient way for CPython
# But a normal 'if' will work
if '__esv6__' in __symbols__:
y = 3
for j in y:
autoTester.check (j)
except: # No 'Exception' can be used behind this, since this is a JavaScript exception, and no subclass of Exception. ??? How desirable is this behaviour?
pass
# autoTester.check ('Detected iterating over non-iterable') # Minifier masks this exception, so we'll have to pass
if '__esv6__' in __symbols__: # "if" rather than "__pragma__ ('ifdef')" because CPython doesn't understand pragma's
autoTester.check ('Issue 122') # Problem with yield (or rather with slicing beyond list end)
def chunks (aList, chunkLength):
for index in range (0, len (aList), chunkLength):
yield aList [index : index + chunkLength]
for chunk in chunks ([chr (index + 97) for index in range (26)], 10):
autoTester.check (chunk)
autoTester.check ('Issue 123') # Python % shouldn't behave like JS %
autoTester.check (10 % 3, 10 % -3, -10 % 3, -10 % -3, 10 % 10, 10 % -10, -10 % 10, -10 % -10)
autoTester.check ('Issue 125') # Strings not iterable
abc = 'abc'
for index in abc:
autoTester.check (abc)
autoTester.check ('Issue 127') # Can't use the key 'keys' in a dict
autoTester.check ({"include_docs": "true", "keys": ["key1", "key2"], "limit": 50})
autoTester.check ('Issue 134') # Operator %= translated incorrectly
x0, x1, x2, x3, x4, x5 = 5, 12, -5, -5, 0, 0
x0 %= 10; x1 %= 5; x2 %= 2; x3 %= -3; x4 %= 1; x5 %= -1000
autoTester.check (x0, x1, x2, x3, x4)
autoTester.check ('Issue 136') # Method dict.get(key[, default]) not implemented
aDict = {'a': 'ape', 'b': 'banana'}
autoTester.check (aDict.get ('a', 'noApe'), aDict.get ('b'), aDict.get ('c', 'noCarot'), aDict.get ('d'))
autoTester.check ('Issue 144')
__pragma__('opov')
aList = [x for x in [1, 2, 3]]
autoTester.check (aList)
__pragma__('noopov')
autoTester.check ('<br><br>Issue 145<br>') # List sorting incorrect in case of multiple columns
class SortTest:
def __init__ (self):
self.alphabet = 'abcdefghijklmnopqrstuvwxyz'
self.nChars = 10
self.nCols = 10
self.nRows = 30
self.pseudoRandom = 0
def randomWord ():
word = ''
for iChar in range (self.nChars):
self.pseudoRandom = (81212 * self.pseudoRandom + 28411) % 134456
# self.pseudoRandom = (1234 * self.pseudoRandom + 57) % 137 # Deliberately short period
word += self.alphabet [self.pseudoRandom % 26]
return word
self.rows = [[randomWord () for iCol in range (self.nCols)] for iRow in range (self.nRows)]
def sort (self):
for iCol in reversed (range (self.nCols)):
self.rows.sort (key = lambda row: row [iCol])
sortTest = SortTest ()
autoTester.check ('<br>Unsorted:<br>')
for row in sortTest.rows:
autoTester.check ('{}<br>'.format (','.join ([word for word in row])))
sortTest.sort ()
autoTester.check ('<br>Sorted:<br>')
for row in sortTest.rows:
autoTester.check ('{}<br>'.format (','.join ([word for word in row])))
autoTester.check ('<br><br>Issue 148<br>') # Allow key a.o. key 'items' in dict
aDict = {
'items': [4, 5, 6]
}
for aKey, aValue in aDict.items ():
autoTester.check ('{}: {}'.format (aKey, aValue))
autoTester.check ('<br><br>Issue 169<br>') # Add support for float('inf') and float('-inf')
autoTester.check (int (1 / float ('inf')), int (1 / float ('-inf')))
autoTester.check ('<br><br>Issue 178<br>') # List Comprehensions / Operator Precedence Bug
bitmaps = [
(2 , ''),
(4 , ''),
(8, 'i'),
(16, 'm'),
(32, 'y'),
(64, 'u'),
(128, 'g')
]
for flags in (122, 233, 11, 55, 79, 201, 23, 111, 200, 100, 50, 25, 12, 6):
autoTester.check (''.join ([x [1] for x in bitmaps if (x [0] & flags) > 0]))
def issue256 ():
autoTester.check ('Issue 256')
class C:
def __init__ (self, value):
self.value = value
def f1 (value): # Generate parens after return
return (C (value) .value or 'second') .capitalize () == 'First'
def f2 (value): # Generate parens after return
return (C (value) .value or 'second') .capitalize () == 'Second'
def f3 (value): # Generate NO parens after return
return C (value) .value or 'second'
def f4 (value): # Generate NO parens after return
return (C (value) .value or 'second')
autoTester.check (f1 ('first'))
autoTester.check (f1 (''))
autoTester.check (f2 ('first'))
autoTester.check (f2 (''))
autoTester.check (f3 ('first'))
autoTester.check (f4 (''))
issue256 ()
autoTester.check ('Issue 274')
a = 3
del a
autoTester.check ('Still alive')
autoTester.check ('Issue 276') # Partial, other part tested in testlet 'operator_overloading'
a = 2
b = a ** 3
a **= 4
autoTester.check (a, b)
autoTester.check ('Issue 277')
new = 3
autoTester.check (new)
autoTester.check ('Issue 279')
class A:
TypeError = 111
js_TypeError = 222
autoTester.check (A.TypeError, A.js_TypeError) # ... Generated code should use py_TypeError and TypeError respectively
autoTester.check ('Still alive')
autoTester.check ('Issue 301')
def filter_word (word0, word1):
if len (word0) != len (word1):
return False
for char0, char1 in zip (word0, word1):
if char0 != '_' and char0 != char1:
return False
return True
autoTester.check (filter_word ('bee', 'beer'))
autoTester.check (filter_word ('wine', 'wine'))
autoTester.check (filter_word ('win_', 'wind'))
autoTester.check (filter_word ('_in_', 'kind'))
autoTester.check (filter_word ('min_', 'kind'))
autoTester.check ('Issue 306')
dict_306 = {'Abraham': 'Lincoln', 'Barack': 'O\'Bama', 'Thomas': 'Jefferson'}
results = []
try:
while True:
results.append (dict_306.popitem ())
except Exception as exception:
autoTester.check (sorted (results))
autoTester.check ('That\'s it')
autoTester.check ('Issue 314')
try:
autoTester.check (int (float (123)))
except:
autoTester.check ('a')
try:
autoTester.check (float (12.3))
except:
autoTester.check ('b')
try:
autoTester.check (int (float ('123')))
except:
autoTester.check ('c')
try:
autoTester.check (int (float (' 123')))
except:
autoTester.check ('d')
try:
autoTester.check (float (''))
except:
autoTester.check ('e')
try:
autoTester.check (float (' '))
except:
autoTester.check ('f')
try:
autoTester.check (float ('drie'))
except:
autoTester.check ('g')
autoTester.check ('Issue 316')
autoTester.check (list (filter (None, [[1, 2], [3], [], [4, 5], [6]])))
autoTester.check (list (filter (lambda l: len (l) >= 2, [[1, 2], [3], [], [4, 5], [6]])))
autoTester.check ('Issue 317')
mylist = []
try:
mylist.remove ('value')
except ValueError as exception:
autoTester.check (exception.__class__.__name__)
autoTester.check ('Issue 331')
autoTester.check (max (-5, 4, 1, 2, -3, 2))
autoTester.check (max ([-5, 4, 1, 2, -3, 2]))
autoTester.check (max ((5, 6, 2, -2, -4)))
autoTester.check (min (-5, 4, 1, 2, -3, 2))
autoTester.check (min ([-5, 4, 1, 2, -3, 2]))
autoTester.check (min ((5, 6, 2, -2, -4)))
autoTester.check ('issue 356')
try:
raise TypeError("How are you?")
except TypeError as exception:
autoTester.check (exception)
#__pragma__ ('ifdef', '__esv6__') # Needed because Transcrypt imports are compile time
if '__esv6__' in __symbols__: # Needed because CPython doesn't understand pragma's
autoTester.check ('Issue 369')
class Vector:
def __init__ (self, *values):
self.values = values
def __iter__ (self):
for item in self.values:
yield item
def __add__(self, other):
return Vector (* (x + y for x, y in zip (self, other)))
def __str__ (self):
return str (list (self.values))
#__pragma__ ('opov')
autoTester.check (str (Vector (1,2,3) + Vector (3,4,5)))
#__pragma__ ('noopov')
#__pragma__ ('endif')
autoTester.check ('Issue 387')
run387 (autoTester)
autoTester.check ('Issue 391')
autoTester.check (int (False))
autoTester.check (int (True))
autoTester.check (int (1 == 2))
autoTester.check (int (1 != 2))
autoTester.check ('Issue 392')
import re
class Example:
d = {'A': 1, 'B': 2}
rec = re.compile ('(?P<decimal>\d+)', re.ASCII)
def run(self):
match = self.rec.match ('42')
if not match:
print('ERROR: RE does not match')
e = match.groupdict ()
autoTester.check ("before: self.d=", self.d)
autoTester.check ("before: e=", e)
self.d.update (e)
autoTester.check ("after: self.d=", self.d)
example = Example ()
example.run ()
autoTester.check ('Issue 398')
# This used to give extra comma's so invalid syntax (no check calls needed)
class Test398 (object):
#__pragma__ ('skip')
def method1 (self):
pass
def method2 (self):
pass
#__pragma__ ('noskip')
pass
test398 = Test398 ()
autoTester.check ('Issue 399')
__pragma__ ('keycheck')
try:
surpressWarning = {'a':5}['a']
surpressWarning = {'a':5}['b']
autoTester.check ('no problem')
except KeyError:
autoTester.check ('not found')
autoTester.check ('Issue 413')
__pragma__ ('nokeycheck')
class Foo:
def __len__ (self):
return 3
def __getitem__ (self, i):
if i >= 3:
raise IndexError
return 'This is item ' + str (i)
foo = Foo ()
#__pragma__ ('opov')
autoTester.check ('Attempt 1:')
for i in foo:
autoTester.check (i)
autoTester.check ('Attempt 2:')
for i in range (len (foo)):
autoTester.check (foo [i])
#__pragma__('noopov')
autoTester.check ('Issue 414')
class Foo:
pass
foo = Foo ()
foo.bar = 'baz'
foo.name = 'hello'
foo.default = 'world'
autoTester.check ([x for x in dir (foo) if not x.startswith ('__')])
#__pragma__('kwargs')
def foo (*args, **kwargs):
default = kwargs.get ('default', 'bar')
return default
autoTester.check (foo())
autoTester.check (foo(default = 'Hello World'))
4.15. Diverse pulls¶
# Also contains small enhancements
'This is a single line docstring'
class A:
'''
This
is
a
multiline
docstring
'''
def __init__ (self, x):
'This is a single line comment'
self.x = x
'''
This
is
a
multiline
docstring
'''
'This is a single line docstring'
'''
This
is
a
multiline
docstring
'''
a = A (5.5)
def run (autoTester):
autoTester.check ('Pull 56')
s = 'abcdefghij'
autoTester.check (s [2:3])
autoTester.check (s [:3])
autoTester.check (s [2:])
autoTester.check (s [::2])
autoTester.check ('Pull 59')
autoTester.check (list (filter (lambda x: x % 2 == 0, range (10))))
autoTester.check (list (map (lambda x: x*x, range (0, 31, 3))))
4.16. Docstrings: __doc__ attribute generated optionally¶
To keep the generated code lean, generation of __doc__ attributes is controlled per module by __pragma__ ('docat') or by the -d / --docat command line switch, combined with user per module of __pragma__ ('nodocat')
'''Just a module
to test docstrings'''
'''Not visible'''
from org.transcrypt.stubs.browser import __pragma__
__pragma__ ('docat')
def run (autoTester):
def f (p):
'''Just a function
called f'''
'''Not visible'''
autoTester.check (p)
class C:
'''Just a class
called C'''
'''Not visible'''
def g (self, q):
'''Just a method
called g'''
'''Not visible'''
autoTester.check (q)
autoTester.check (__doc__)
autoTester.check ()
autoTester.check (f.__doc__)
autoTester.check ()
autoTester.check (C.__doc__)
autoTester.check ()
autoTester.check (C.g.__doc__)
autoTester.check ()
f ('Doc')
C () .g ('strings')
4.17. Exceptions: exception class hierarchy, finally¶
from org.transcrypt.stubs.browser import __envir__, __new__, __pragma__
if __envir__.executor_name == __envir__.transpiler_name:
class BaseException: # ??? Make part of __builtins__ for CPython compliance?
pass
class Ex1 (Exception):
pass
class Ex2 (Ex1):
pass
class Ex3 (Exception):
pass
class Table (BaseException): # Any Python exception MUST inherit from BaseException
def __init__ (self, *args):
self.fields = args
def __repr__ (self):
return 'Table' + repr (self.fields) .replace (', ', ',') .replace ('\'', '')
def test1 ():
raise (Exception ('mary'))
def test2 (autoTester):
try:
test1 ()
except Ex1 as exception:
autoTester.check (111)
autoTester.check (exception)
except Exception as exception:
autoTester.check (222)
autoTester.check (exception)
def run (autoTester):
test2 (autoTester)
try:
raise Ex2 ('had')
except Ex1 as exception:
autoTester.check ('a')
except Exception as exception:
autoTester.check ('little')
autoTester.check (exception)
autoTester.check (333)
try:
raise Ex1 ('lamb')
except Ex2 as exception:
autoTester.check ('his')
autoTester.check (exception)
except Ex1 as exception:
autoTester.check ('fleece')
autoTester.check (exception)
except Exception as exception:
autoTester.check ('was')
autoTester.check (exception)
finally:
autoTester.check ('white')
autoTester.check (444)
def test3 ():
raise Ex3 ('as')
autoTester.check (555)
try:
test3 ()
except Ex1 as exception:
autoTester.check ('snow')
autoTester.check (exception)
except Exception as exception:
autoTester.check ('and')
autoTester.check (exception)
finally:
autoTester.check ('everywhere')
autoTester.check (666)
try:
raise Ex3 ('that')
except Ex1 as exception:
autoTester.check ('mary')
autoTester.check (exception)
except:
autoTester.check ('went')
finally:
autoTester.check ('the')
autoTester.check (777)
try:
try:
raise Ex3 ('lamb')
except Ex1 as exception:
autoTester.check ('was')
autoTester.check (exception)
finally:
autoTester.check ('to')
except Ex3 as exception: # We should get here, exception not swallowed
autoTester.check ('go')
autoTester.check (exception)
try:
raise __new__ (Table ('he', 'followed', 'her'))
except Ex1 as exception:
autoTester.check ('to')
autoTester.check (exception)
except Table as exception: # Pure JavaScript exception, if no Python __class__
autoTester.check ('school')
autoTester.check (exception)
except Ex3 as exception:
autoTester.check ('one')
autoTester.check (exception)
finally:
autoTester.check ('day')
try:
assert 2 * 8 / 4 == 2, 'Assert error 1'
except AssertionError as exception:
autoTester.check (exception)
try:
assert 2 * 8 / 4 == 4, 'Assert error 2'
except AssertionError as exception:
autoTester.check (exception)
try:
assert 2 * 8 / 4 == 2
except AssertionError as exception:
autoTester.check (exception)
try:
assert 2 * 8 / 4 == 4
except AssertionError as exception:
autoTester.check (exception)
autoTester.check (888)
try:
autoTester.check ('hello world 1')
except:
autoTester.check ('error 1')
else:
autoTester.check ('no error 1')
i = 1 + 2
try:
autoTester.check ('hello world 2')
if i == 3: # Prevent unreachable code warning
raise Exception ()
except:
autoTester.check ('error 2')
else:
autoTester.check ('no error 2')
for raiseIt in (False, True):
try:
try:
if raiseIt:
raise Exception ()
autoTester.check ('no error 3')
finally:
autoTester.check ('anyhow 3')
except:
autoTester.check ('error 3')
4.18. Extended slices: facilitating NumScrypt and such¶
from org.transcrypt.stubs.browser import *
from org.transcrypt.stubs.browser import __pragma__, __envir__
def indices (key):
if __envir__.executor_name == __envir__.transpiler_name:
return tuple (key) if type (key) == list else key
else:
try:
return key.indices (1000000000)
except:
try:
return tuple ([indices (subkey) for subkey in key])
except:
return key
class Test:
def __init__ (self, autoTester):
self.autoTester = autoTester
def __getitem__ (self, key):
self.autoTester.check ('getitem (', indices (key), ')')
return 1234567
def __setitem__ (self, key, value):
self.autoTester.check ('setitem (', indices (key), ')', value)
def run (autoTester):
a = b = c = d = e = f = g = h = i = j = k = l = Test (autoTester)
__pragma__ ('opov')
a [1:2:3, 4:5:6] = b [7:8:9]
c [1:2:3] = d [4:5:6, 7:8:9]
e [1, 1:2:3, 3] = f [4, 4:5:6, 6]
g [1, 2, 3] = h [1, 2, 3]
i [1] = j [1]
k [1:2:3] = l [1:2:3]
4.19. General functions: sort and sorted¶
from org.transcrypt.stubs.browser import __pragma__
class A:
foo='bar'
def __init__ (self):
self.foo2 = 'bar2'
class B (A):
foo3='bar3'
def __init__ (self):
self.foo4 = 'bar4'
class C:
def __len__ (self):
return 42
def run (autoTester):
autoTester.check ('len')
strings = ['hello', ',', 'world', '!']
instances = [C()]
collections = [
[], [1], [1, 2],
tuple(), (1,), (1, 2),
{}, {1: 1}, {1: 1, 2: 2}
]
for string in strings:
autoTester.check (len (string))
for instance in instances:
autoTester.check (len (instance))
for collection in collections:
autoTester.check (len (collection))
autoTester.check ('sort and sorted<br>')
a = [1, 5, 3, 2, -1]
b = ['sun', 'earth', 'moon']
autoTester.check (sorted (a))
autoTester.check (sorted (b))
a.sort ()
autoTester.check (a)
b.sort ()
autoTester.check (b)
autoTester.check (sorted (a, reverse = True))
autoTester.check (sorted (b, reverse = True))
a.sort (reverse = True)
autoTester.check (a)
b.sort (reverse = True)
autoTester.check (b)
b.sort (key = lambda x: len (x))
autoTester.check (b)
b.sort (key = lambda x: len (x), reverse = True)
autoTester.check (b)
autoTester.check ('<br><br>dir<br>')
autoTester.check ([entry for entry in dir (A) if not entry.startswith ('__')])
autoTester.check ([entry for entry in dir (A()) if not entry.startswith ('__')])
autoTester.check ([entry for entry in dir (B) if not entry.startswith ('__')])
autoTester.check ([entry for entry in dir (B()) if not entry.startswith ('__')])
autoTester.check ('<br><br>any, all, sum<br>')
list1 = ['ape', 'node', 'mice']
list2 = ['vim', '', 'jet']
list3 = ['', '', '']
list4 = [[1, 2], [1], []] # Truthyness into play
autoTester.check (list1, any (list1), all (list1))
autoTester.check (list2, any (list2), all (list2))
autoTester.check (list3, any (list3), all (list3))
autoTester.check (list4, any (list4), all (list4))
autoTester.check (sum (range (5)))
__pragma__ ('ifdef', '__esv6__')
if '__esv6__' in autoTester.symbols:
def generator1 ():
for i in range (5):
yield i;
def generator2 ():
for i in range (5):
if i % 2:
yield 0
else:
yield i;
def generator3 ():
for i in range (5):
yield 0;
autoTester.check (generator1 (), any (generator1 ()), all (generator1 ()))
autoTester.check (generator2 (), any (generator2 ()), all (generator2 ()))
autoTester.check (generator3 (), any (generator3 ()), all (generator3 ()))
autoTester.check (sum (generator1 ()))
__pragma__ ('endif')
4.20. Global variable access by using globals () [<variable_name>]¶
The globals () function does the same as its counterpart in CPython, with some restrictions.
In the same module:
- globals () can retrieve all module-level variables, wether created via globals () or in the normal way
- module-level variables created via globals () can only be retrieved by globals (), not as a normal variable
From a different module:
- globals () can retrieve all module-level variables, wether created by globals () or in the normal way
- module-level variables created by globals () can be retrieved by globals (), but also as a normal variable
Since imports are done (statically) at compile time, from ... import * will not include the variables created (dynamically) via globals (). You can however import the whole module, e.g. import <longName> as <shortName> and then use <shortName>.<dynamicallyCreatedVariable>.
The code below shows what's possible:
xxa = 'subXxa'
xxb = 'subXxb'
for name in ('xxp', 'xxq'):
globals () [name] = 'sub{}'.format (name.capitalize ())
def f ():
for name in ('xxr', 'xxs'):
globals () [name] = 'sub{}'.format (name.capitalize ())
def run (autoTester):
f ()
autoTester.check ('Check sub 1', xxa, xxb)
autoTester.check ('Check sub 2', * [globals () [name] for name in ('xxa', 'xxb', 'xxp', 'xxq', 'xxr', 'xxs')])
autoTester.check ('Check sub 3', * sorted ([value for key, value in globals () .items () if key.startswith ('xx')]))
from globals_function import sub
xxa = 'mainXxa'
xxb = 'mainXxb'
for name in ('xxp', 'xxq'):
globals () [name] = 'main{}'.format (name.capitalize ())
def f ():
for name in ('xxr', 'xxs'):
globals () [name] = 'main{}'.format (name.capitalize ())
def run (autoTester):
f () # All vars of main added
sub.run (autoTester) # Shouldn't override vars of main
autoTester.check ('Check main 1', xxa, xxb)
autoTester.check ('Check main 2', * [globals () [name] for name in ('xxa', 'xxb', 'xxp', 'xxq', 'xxr', 'xxs')])
autoTester.check ('Check main 3', sub.xxa, sub.xxb, sub.xxp, sub.xxq, sub.xxr, sub.xxs)
autoTester.check ('Check main 4', * sorted ([value for key, value in globals () .items () if key.startswith ('xx')]))
The output will be:

4.21. Indices and slices: LHS, RHS, basic and extended¶
def run (autoTester):
# Right hand side slices
all = range (32)
autoTester.check (all)
autoTester.check (all [8 : 24])
autoTester.check (all [8 : 24 : 2])
# Left hand side slices
aList = [3, 4, 7, 8]
autoTester.check (aList)
aList [4 : 4] = [9, 10]
autoTester.check (aList)
aList [2 : 2] = [5, 6]
autoTester.check (aList)
aList [0 : 0] = [1, 2]
autoTester.check (aList)
aList [ : : 2] = [x + 0.001 for x in range (10) if x % 2]
autoTester.check (aList)
4.22. Iterators and generators¶
from org.transcrypt.stubs.browser import __pragma__
class Iterable:
def __init__ (self, i):
self.aList = range (0, 50, i)
def __iter__ (self):
return Iterator (self)
class Iterator:
def __init__ (self, iterable):
self.iterable = iterable
self.index = -1
def __next__ (self): # Should be auto-wrapped in a next (self) by the compiler
self.index += 1
if self.index > 5:
raise StopIteration ()
return self.iterable.aList [self.index]
def __iter__ (self):
return self
def exhaustableGenerator (i):
for i in range (5):
yield 2 * i
def run (autoTester):
exhaustableGenExp = (a * a * a for a in [10, 20, 30]) # Currently still converted to iterator on list comprehension, must also be iterable
# So becomes py_iter (aList).
# List already has an __iter__ which it will return, it's a __PyIterator__
# To that __PyIterator__, that will already have a __next__, py_iter first adds a next
# So exhaustableGenExp is an iterator with a next and a __next__
# If we call iter on that, py_iter is calle again py_iter, on an object with a next and a next __next__
# For this reason py_iter needs a recursion prevention check
iterables = [Iterable (7), exhaustableGenerator (5), [i * 3 for i in range (5)], exhaustableGenExp]
for iterable in iterables:
autoTester.check ('[1]')
iterator = iter (iterable)
try:
while True:
autoTester.check (next (iterator))
except Exception as exception:
autoTester.check (exception.__class__.__name__)
autoTester.check ('[2]')
iterator = iter (iterable)
try:
while True:
autoTester.check (next (iterator))
except Exception as exception:
autoTester.check (exception.__class__.__name__)
for iterable in iterables:
autoTester.check ('[3]')
for n in iterable:
autoTester.check (n)
autoTester.check ('[4]')
for n in iterable:
autoTester.check (n)
# BEGIN issue 196: for loop over iter (), runs OK but needs JavaScript 6. This should be clearly in the docs.
a = 0
vals = [1,2,3]
ret = iter (vals)
for m in ret:
a += m
autoTester.check (a)
# END issue 196
# BEGIN 1st example with 'send'
__pragma__ ('gsend')
def test0 ():
r = 0
while True:
r = r + (yield r)
gen0 = test0()
next (gen0)
autoTester.check (gen0.send (1))
autoTester.check (gen0.send (2))
def test1 ():
r = 0
while True:
r = (yield r) + r
gen1 = test1()
next (gen1)
autoTester.check (gen1.send (3))
autoTester.check (gen1.send (4))
# END 1st example with 'send'
def subGenerator ():
yield 27
yield 37
yield 47
def mainGenerator ():
yield 17
yield from subGenerator ()
yield 57
autoTester.check (* [i for i in mainGenerator ()])
def subCoroutine ():
autoTester.check (38)
yield
autoTester.check (48)
yield
autoTester.check (58)
yield
autoTester.check (68)
def mainCoroutine ():
autoTester.check (18)
yield
autoTester.check (28)
yield from subCoroutine ()
autoTester.check (78)
yield
autoTester.check (88)
m = mainCoroutine ()
for i in range (5):
m.send (None)
4.23. Lambda functions with all types of args¶
def run (autoTester):
z = 1000
autoTester.check ((lambda x, y: x + y + z) (111, 222))
def f (list0, list1, aFunc):
return [aFunc (*elem) for elem in zip (list0, list1)]
x = f (range (10), range (0, 100, 10), lambda x, y: x + y + z)
autoTester.check (x)
autoTester.check (f (range (10, 20), range (100, 200, 10), lambda x, y: x * y + 100 * z))
autoTester.check (f (range (10, 20), range (100, 200, 10), lambda *args: args [0] * args [1] + 100 * z))
4.24. List comprehensions: multi-loop and nested with multiple if's¶
def run (autoTester):
squares = [i * i for i in range (10) if i % 2]
autoTester.check (squares)
tuples = [
(x, y, z)
for x in (100, 200, 300, 400, 500, 600, 700)
for y in (10, 20, 30, 40, 50, 60, 70) if 20 < y < 60
for z in (1, 2, 3, 4, 5, 6, 7) if 200 < x < 600 if 2 < z < 6
]
autoTester.check (tuples)
tricky = [(2 * x, 3 * y) for x, y in ((10, 11), (20, 21))]
autoTester.check (tricky)
nested = [2 * x for x in [x * x for x in range (3)]]
autoTester.check (nested)
a = 100
x = 5
scopeTest = [x + a for x in range (5)]
autoTester.check (x)
autoTester.check (scopeTest)
4.25. Local classes: inside other classes and functions¶
def run (autoTester):
class A:
class B:
class C:
def __init__ (self, x):
self.x = x
def tell (self):
autoTester.check (self.x)
autoTester.check (self.e)
# Limitation: no destructuring assignment inside nested classes
e = 3
def __init__ (self, x):
self.x = x
def tell (self):
autoTester.check (self.x)
autoTester.check (self.d)
d = 2
c = 1
def __init__ (self, x):
self.x = x
def tell (self):
autoTester.check (self.x)
autoTester.check (self.c)
def f (x):
class G:
class H:
def __init__ (self, x):
self.x = x
def tell (self):
autoTester.check (self.x)
autoTester.check (self.i)
i = 5
def __init__ (self, x):
self.x = x
def tell (self):
autoTester.check (self.x)
k = 4
g = G (6)
g.tell ()
autoTester.check (g.k)
h = G.H (7)
h.tell ()
autoTester.check (h.i)
class P (A.B):
pass
p = P (7)
p.tell ()
autoTester.check (p.d)
a = A (8)
b = a.B (9)
c = b.C (10)
a.tell ()
b.tell ()
c.tell ()
autoTester.check (a.c)
autoTester.check (b.d)
f (7)
4.26. Metaclasses: overriding type.__new__ in a descendant metaclass¶
from org.transcrypt.stubs.browser import __pragma__
class UppercaserMeta (type):
def __new__ (meta, name, bases, attribs):
__pragma__ ('jsiter') # Translate for ... in directly to JavaScript for ... in ... and translate {} to bare {} rather than to dict {}
# Using bare {} as attribs parameter to __new__ avoids dict attributes masking regular attributes
# For more flexibility use __pragma__ ('js', '{}', '''...''')
upperAttribs = {}
for attribKey in attribs: # Translates to 'for (var attribKey in attribs)' by virtue of __pragma__ ('jsiter'), to iterate over the attributes of a bare JavaScript {}
upperAttribs [attribKey if attribKey.startswith ('__') else attribKey.upper ()] = attribs [attribKey]
__pragma__ ('nojsiter')
return type.__new__ (meta, name, bases, upperAttribs)
class Uppercaser (metaclass = UppercaserMeta):
pass
class Animal (Uppercaser):
class Thoughts:
quantity = 7
# Limitation: no destructuring assignment if metaclass has to alter attributes
color = 'Brown'
state = 'Moving'
def move (self):
return 'Move'
class Plant (Uppercaser):
class Thoughts:
quantity = 6
color = 'Green'
state = 'Growing'
def grow (self):
return 'Grow'
class Stone:
class Thoughts:
quantity = 5
color = 'Gray'
def be (self):
return ('Being')
def run (autoTester):
animal = Animal ()
autoTester.check (animal.THOUGHTS.quantity, Animal.COLOR, animal.COLOR, animal.MOVE ())
plant = Plant ()
autoTester.check (plant.THOUGHTS.quantity, Plant.COLOR, plant.COLOR, plant.GROW ())
stone = Stone ()
autoTester.check (stone.Thoughts.quantity, Stone.color, stone.color, stone.be ())
4.27. Module builtin: a small part of it demo'ed¶
# coding: utf-8
from org.transcrypt.stubs.browser import __envir__
def canonizeString (aString):
if __envir__.executor_name == 'transcrypt':
return aString.replace ('\t', '\\t') .replace ('\n', '\\n')
else:
return aString
def canonizeStringList (stringList):
return [canonizeString (aString) for aString in stringList]
def run (autoTester):
autoTester.check ('min', min (-1.1, -1, -3))
autoTester.check ('max', max (-1.1, -1, -3))
autoTester.check ('abs', abs (-1), abs (1), abs (0), abs (-0.1), abs (0.1))
autoTester.check ('ord', ord ('a'), ord ('e´'[0])) # This is the 2 codepoint version
autoTester.check ('round',
round (4.006),
round (4.006, 2),
round (4060, -2),
round (-4.006),
round (-4.006, 2),
round (-4060, -2),
round (1/2.),
round (1/2., 1),
round (1/2, 1),
round (1/3., 2),
round (-1/2.),
round (-1/2., 1),
round (-1/2, 1),
round (-1/3., 2),
round (0.5),
round (0.51),
round (1.5),
round (1.51),
round (1.51),
round (2.5),
round (2.59),
round (3.5),
round (3.59),
round (-0.5),
round (-0.51),
round (-1.5),
round (-1.51),
round (-1.51),
round (-2.5),
round (-2.59),
round (-3.5),
round (-3.59)
)
strings = [
'der des dem den die der den die das des dem das',
'an auf hinter ueber neben vor zwischen',
'''
durch
fuer
ohne
um
bis
gegen
entlang
''',
'eins,zwei,drie,vier,fuenf,sechs,sieben'
]
autoTester.check ('<br><br>split')
for aString in strings:
autoTester.check (
canonizeString (aString),
canonizeStringList (aString.split ()),
canonizeStringList (aString.split (' ')),
canonizeStringList (aString.split (' ', 4)),
canonizeStringList (aString.split ('\t')),
canonizeStringList (aString.split ('\t', 4)),
canonizeStringList (aString.split ('\n')),
canonizeStringList (aString.split ('\n', 4)),
canonizeStringList (aString.split (',')),
canonizeStringList (aString.split (',', 4)),
'<br>'
)
autoTester.check ('<br>rsplit')
for aString in strings:
autoTester.check (
canonizeString (aString),
canonizeStringList (aString.rsplit ()),
canonizeStringList (aString.rsplit (' ')),
canonizeStringList (aString.rsplit (' ', 4)),
canonizeStringList (aString.rsplit ('\t')),
canonizeStringList (aString.rsplit ('\t', 4)),
canonizeStringList (aString.rsplit ('\n')),
canonizeStringList (aString.rsplit ('\n', 4)),
canonizeStringList (aString.rsplit (',')),
canonizeStringList (aString.rsplit (',', 4)),
'<br>'
)
autoTester.check("".isalpha())
autoTester.check("123".isalpha())
autoTester.check("abc".isalpha())
autoTester.check("abc123".isalpha())
4.28. Module cmath: allmost all of Python's cmath module¶
from org.transcrypt.stubs.browser import __pragma__
from cmath import *
twoPi = 2 * pi
nDecs = 5
__pragma__ ('opov')
def run (autoTester):
autoTester.check (phase (1 + 1j))
aPolar = polar (3 + 5j)
autoTester.check (round (aPolar [0], nDecs), aPolar [1])
aRect = rect (*aPolar)
autoTester.check (round (aRect.real), round (aRect.imag))
anExp = exp (-2.2 - 3.3j)
autoTester.check (round (anExp.real, nDecs), round (anExp.imag, nDecs))
aLog = log (anExp)
autoTester.check (round (aLog.real, nDecs), round (aLog.imag, nDecs))
anExp10 = aLog ** 10
autoTester.check (round (anExp10.real, nDecs), round (anExp10.imag, nDecs))
aLog10 = log10 (anExp10)
autoTester.check (round (aLog10.real, nDecs), round (aLog10.imag, nDecs))
anExpRect = aLog ** aRect
autoTester.check (round (anExpRect.real, nDecs), round (anExpRect.imag, nDecs))
aLogRect = log (anExpRect, aRect)
autoTester.check (round (aLogRect.real, nDecs), round (aLogRect.imag, nDecs))
aSqrt = sqrt (1j)
autoTester.check (round (aSqrt.real, nDecs), round (aSqrt.imag, nDecs))
autoTester.check (sqrt (4))
anotherSqrt = sqrt (-4)
autoTester.check (round (anotherSqrt.real), round (anotherSqrt.imag))
anAsin = asin (1 + 2j)
autoTester.check (round (anAsin.real, nDecs), round (anAsin.imag, nDecs))
anAcos = acos (-2 + 3j)
autoTester.check (round (anAcos.real, nDecs), round (anAcos.imag, nDecs))
anAtan = atan (3 - 4j)
autoTester.check (round (anAtan.real, nDecs), round (anAtan.imag, nDecs))
aSin = sin (anAsin)
autoTester.check (round (aSin.real), round (aSin.imag))
aCos = cos (anAcos)
autoTester.check (round (aCos.real), round (aCos.imag))
aTan = tan (anAtan)
autoTester.check (round (aTan.real), round (aTan.imag))
anAsinh = asinh (aCos)
autoTester.check (round (anAsinh.real, nDecs), round (anAsinh.imag, nDecs))
anAcosh = acosh (aSin)
autoTester.check (round (anAcosh.real, nDecs), round (anAcosh.imag, nDecs))
anAtanh = atanh (aTan)
autoTester.check (round (anAtanh.real, nDecs), round (anAtanh.imag, nDecs))
aSinh = sinh (anAsinh)
autoTester.check (round (aSinh.real), round (aSinh.imag))
aCosh = cosh (anAcosh)
autoTester.check (round (aCosh.real), round (aCosh.imag))
aTanh = tanh (anAtanh)
autoTester.check (round (aTanh.real), round (aTanh.imag))
4.29. Module itertools: allmost all of Python's itertools module¶
from itertools import *
from math import pow
def fibonacci():
a, b = 0, 1
for i in range (10):
yield a
a, b = b, a + b
squares = [i * i for i in range (10)]
chars = 'thequickbrownfoxjumpsoverthelazydog'
def run (autoTester):
autoTester.check ('islice count', list (islice (count (10, 2), 4, 40, 3)))
autoTester.check ('islice cycle', list (islice (cycle (fibonacci ()), 15)))
autoTester.check ('repeat', list (repeat (3.14, 15)))
autoTester.check ('islice repeat', list (islice (repeat (2.74), 15)))
autoTester.check ('accumulate', list (accumulate (range (5))))
def add (total, element):
return total + element
autoTester.check ('accumulate', list (accumulate (['alamak', 'mirach', 'sirrah'], add)))
autoTester.check ('chain', list (chain (fibonacci (), squares, chars)))
autoTester.check ('chain.from_iterable', list (chain.from_iterable (['ape', 'node', 'mice', 'vim', 'sus', 'jet'])))
selectors = [True, True, False, True, False, False, True, True, False, True]
autoTester.check ('compress', list (compress (
['{}{}'.format (('take' if selector else 'leave'), index) for index, selector in enumerate (selectors)],
selectors
)))
autoTester.check ('dropwhile', list (dropwhile (lambda x: x < 5, [1, 4, 6, 4, 1])))
autoTester.check ('filterfalse', list (filterfalse (lambda x: x % 2, range (10))))
things = [('animal', 'bear'), ('animal', 'duck'), ('plant', 'cactus'), ('vehicle', 'speed boat'), ('vehicle', 'school bus')]
for key, group in groupby (things, lambda x: x [0]):
for thing in group:
autoTester.check ('A {} is a {}.' .format (thing[1], key))
autoTester.check (' ')
autoTester.check ('islice', list (islice ([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2, 9, 2)))
autoTester.check ('starmap', [int (x) for x in starmap (pow, [(2, 5), (3, 2), (10, 3)])])
autoTester.check ('takewhile', list (takewhile (lambda x: x < 5, [1, 4, 6, 4, 1])))
i1, i2 = tee (islice (count (), 5))
autoTester.check ('tee', list (i1), list (i1), list (i2))
autoTester.check ('product', list (product ('ABCD', 'xy')), list (product (range (2), repeat = 3)))
autoTester.check ('permutations', list (permutations ('ABCD')), list (permutations ('ABCD', 2)))
autoTester.check ('combinations',
list (combinations ('ABCD', 2)),
list (combinations ([1, 2, 3, 4, 5], 3)),
list (combinations (islice (count (), 6), 4))
)
autoTester.check ('combinations_with_replacement',
list (combinations_with_replacement ('ABCD', 2)),
list (combinations_with_replacement ([1, 2, 3, 4, 5], 3)),
list (combinations_with_replacement (islice (count (), 6), 4))
)
4.30. Module math: allmost all of Python's math module¶
from math import *
def _check(nr, autoTester):
# we just compare the first 15 digits of floats due to precision deviations
# in browser and CPython:
if isinstance(nr, float):
nr = str(nr)[:15]
autoTester.check(nr)
def run (autoTester):
check = lambda nr: _check(nr, autoTester)
check (pi)
check (e)
check (exp (3))
check (int (expm1 (5)))
check (log (0.2))
check (round (log (1024, 2)))
check (log1p (5))
check (int (log2 (257)))
check (int (log10 (1001)))
check (pow (3, 4.5))
check (sqrt (25.1))
check (sin (10))
check (cos (10))
check (tan (10))
check (asin (0.5))
check (acos (0.5))
check (atan (0.5))
check (atan2 (1, 2))
check (int (hypot (3, 4.1)))
check (degrees (pi/2.1))
check (radians (90))
check (sinh (1))
check (cosh (1))
check (tan (1))
check (asinh (70))
check (acosh (70))
check (atan (70))
check (floor (3.5))
check (ceil (3.5))
check (trunc (3.5))
check (isnan (3))
check (isnan (nan))
4.31. Module random: most important functions of Python's random module¶
from random import *
result = ''
def output (any):
result += any + '<br>\n'
for fixedSeed in (False, True):
if fixedSeed:
seed (3)
else:
seed ()
output ('------ {} ------'.format ('fixed seed' if fixedSeed else 'auto seed'))
output ('--- randint ---')
for i in range (20):
output (randint (10, 20))
output ('<br>\n--- choice ---')
for i in range (20):
output (choice ([1, 2, 3, 4, 5]))
output ('<br>\n--- random ---')
for i in range (20):
output (random ())
output ('<br>\n--- shuffle ---')
aList = [0, 1, 2, 3, 4, 5, 6]
output (aList)
for i in range (7):
shuffle (aList)
output (aList)
output ('<br>\n')
document.getElementById ('output') .innerHTML = result
4.32. Modules: hierarchical, both local to the project and global url-based¶
import modules.mod1.mod11.mod111
import modules.mod3
import modules.mod1.mod11.mod112
import modules.mod1
import modules.mod1.mod11
import modules.mod2
import modules.mod2.mod21
import modules.mod2.mod22
import modules.mod1.mod11.mod111 as aliasMod111
import modules.mod1 as aMod1
from modules.mod1.mod11 import mod111, mod112
from modules.mod2 import mod21 as aMod21, mod22 as aMod22
from modules.mod3 import *
from modules.mod1.mod11.mod111 import A
a = modules.mod1.mod11.mod111.A (12345)
pi = modules.mod1.pi
f = modules.mod2.f
def run (autoTester):
# Import without 'as'
autoTester.check ('modules')
autoTester.check (a.f ())
autoTester.check (modules.mod1.mod11.mod112.f ())
autoTester.check (modules.mod1.mod11.e)
autoTester.check (pi)
autoTester.check (f (102030))
autoTester.check (modules.mod2.mod21.f ())
B = modules.mod2.mod22.B
b = B ()
autoTester.check (b.x)
autoTester.check (modules.mod3.x)
# Import with 'as'
a2 = aliasMod111.A (6789101112)
autoTester.check (a2.f ())
autoTester.check (aMod1.pi)
# From ... import without 'as'
a3 = mod111.A (100.001)
autoTester.check (a3.f ())
autoTester.check (mod112.f ())
# From ... import with 'as'
autoTester.check (aMod21.f ())
autoTester.check (aMod22.B () .x)
# From ... import *
autoTester.check (mod3Hundred)
autoTester.check (mod3GetTwoHundred ())
autoTester.check (A (123.321) .f ())
from modules import mod4
# From ... import within function, with circular import
autoTester.check(mod4.mod4Add2FromMod5(449))
4.33. Nonlocals¶
def run (autoTester):
test1 = 1
test2 = 2
def f ():
test1 = 10
nonlocal test2
test2 = 20
autoTester.check (test1, test2)
f ()
autoTester.check (test1, test2)
4.34. Operator overloading¶
from org.transcrypt.stubs.browser import __pragma__
class Matrix:
def __init__ (self, nRows, nCols, elements = []):
self.nRows = nRows
self.nCols = nCols
if len (elements):
self._ = elements
else:
self._ = [[0 for col in range (nCols)] for row in range (nRows)]
def __matmul__ (self, other):
result = Matrix (self.nRows, other.nCols)
for iTargetRow in range (result.nRows):
for iTargetCol in range (result.nCols):
for iTerm in range (self.nCols):
result._ [iTargetRow][iTargetCol] += self._ [iTargetRow][iTerm] * other._ [iTerm][iTargetCol]
return result
def __imatmul__ (self, other):
# True in-place multiplication not yet implemented in compiler
# It currently translates m1 @= m2 to m1 = m1 @ ms and uses __matmul__ instead
# This fake __imatmul__ is just for CPython , allowing back to back testing
return self.__matmul__ (other)
def __mul__ (self, other):
if type (other) == Matrix:
result = Matrix (self.nRows, self.nCols)
for iRow in range (self.nRows):
for iCol in range (self.nCols):
result._ [iRow][iCol] = self._ [iRow][iCol] * other._ [iRow][iCol]
return result
else: # other is a scalar
return self.__rmul__ (other)
def __rmul__ (self, scalar): # Only called if left operand is scalar, all other cases will call __mul__
result = Matrix (self.nRows, self.nCols)
for iRow in range (self.nRows):
for iCol in range (self.nCols):
result._ [iRow][iCol] = scalar * self._ [iRow][iCol]
return result
def __imul__ (self, other):
return self.__mul__ (other)
def __add__ (self, other):
result = Matrix (self.nRows, self.nCols)
for iRow in range (self.nRows):
for iCol in range (self.nCols):
result._ [iRow][iCol] = self._ [iRow][iCol] + other._ [iRow][iCol]
return result
# No __iadd__, to test fallback to __add__
def __getitem__ (self, index):
return self._ [index]
def __setitem__ (self, index, value):
self._ [index] = value
def __repr__ (self):
return repr (self._)
def __floordiv__ (self, other):
return 'Overloading __floordiv__ has no meaning for matrices'
def __truediv__ (self, other):
return 'Overloading __truediv__ has no meaning for matrices'
class Functor:
def __init__ (self, factor):
self.factor = factor
__pragma__ ('kwargs')
def __call__ (self, x, y = -1, *args, m = -2, n, **kwargs):
return (
self.factor * x,
self.factor * y,
[self.factor * arg for arg in args],
self.factor * m,
self.factor * n,
# !!! [self.factor * kwargs [key] for key in sorted (kwargs.keys ())] Add supoprt for keys () on kwargs
)
__pragma__ ('nokwargs')
f = Functor (10)
__pragma__ ('kwargs')
def g (x, y = -1, *args, m = -2, n, **kwargs):
return (x, y, args, m, n) # !!! , [kwargs [key] for key in sorted (kwargs.keys ())]) Add support for keys () on kwargs
__pragma__ ('nokwargs')
def run (autoTester):
m0 = Matrix (3, 3, [
[1, 2, 3],
[4, 5, 6],
[7, 8, 10]
])
m1 = Matrix (3, 3, [
[10, 20, 30],
[40, 50, 60],
[70, 80, 90]
])
m4 = Matrix (3, 3, [
[1, 1, 2],
[2, 2, 3],
[3, 3, -5]
])
m5 = Matrix (3, 3, [
[1, 1, 2],
[2, 2, 3],
[3, 3, -5]
])
x = 3
y = x * 4 * x
fast = 2 * 3
fast += 1
__pragma__ ('opov')
m1 [1][2] = m0 [1][2]
slow = 2 + 3
m2 = m0 * m1 + m1 * (m0 + m1)
m3 = 2 * (2 * m0 * 3 * m1 + m2 * 4) * 2
autoTester.check (m0 [1][1], m0 [1][2], m1 [1][1], m1 [1][2])
m1 += m0
m2 *= m1
m5 @= m4
m6 = m0 @ m1
autoTester.check (m0 / m1)
autoTester.check (m0 // m1)
__pragma__ ('noopov')
fast2 = 16 * y + 1
fast *= 2
autoTester.check (m0, m1)
autoTester.check (x, y)
autoTester.check (m2)
autoTester.check (m3)
autoTester.check (m5)
autoTester.check (m6)
autoTester.check (fast, slow, fast2)
x = 'marker'
__pragma__ ('opov')
autoTester.check (f (3, 4, 30, 40, m = 300, n = 400, p = 3000, q = 4000))
autoTester.check (g (3, 4, 30, 40, m = 300, n = 400, p = 3000, q = 4000))
autoTester.check (set ((1, 2, 3)) == set ((3, 2, 1)))
autoTester.check (set ((1, 2, 3)) != set ((3, 2, 1)))
autoTester.check (set ((1, 3)) == set ((3, 2, 1)))
autoTester.check (set ((1, 3)) != set ((3, 2, 1)))
autoTester.check (set ((1, 2)) < set ((3, 2, 1)))
autoTester.check (set ((1, 2, 3)) <= set ((3, 2, 1)))
autoTester.check (set ((1, 2, 3)) > set ((2, 1)))
autoTester.check (set ((1, 2, 3)) >= set ((3, 2, 1)))
autoTester.check ((1, 2, 3) == (1, 2, 3))
autoTester.check ([1, 2, 3] == [1, 2, 3])
autoTester.check ((1, 2, 3) != (1, 2, 3))
autoTester.check ([1, 2, 3] != [1, 2, 3])
autoTester.check ((2, 1, 3) == (1, 2, 3))
autoTester.check ([2, 1, 3] == [1, 2, 3])
autoTester.check ((2, 1, 3) != (1, 2, 3))
autoTester.check ([2, 1, 3] != [1, 2, 3])
__pragma__ ('noopov')
class Bitwise:
def __lshift__ (self, other):
autoTester.check ('lshift')
def __rlshift__ (self, other):
autoTester.check ('rlshift')
def __rshift__ (self, other):
autoTester.check ('rshift')
def __rrshift__ (self, other):
autoTester.check ('rrshift')
def __or__ (self, other):
autoTester.check ('or')
def __ror__ (self, other):
autoTester.check ('ror')
def __xor__ (self, other):
autoTester.check ('xor')
def __rxor__ (self, other):
autoTester.check ('rxor')
def __and__ (self, other):
autoTester.check ('and')
def __rand__ (self, other):
autoTester.check ('rand')
bitwise = Bitwise ()
__pragma__ ('opov')
bitwise << []
[] << bitwise
autoTester.check (32 << 2)
bitwise >> []
[] >> bitwise
autoTester.check (32 >> 2)
bitwise | []
[] | bitwise
autoTester.check (1 | 4)
bitwise ^ []
[] ^ bitwise
autoTester.check (11 ^ 13)
bitwise & []
[] & bitwise
autoTester.check (12 & 20)
a = 32
a <<=2
autoTester.check (a)
__pragma__ ('noopov')
autoTester.check (32 << 2)
autoTester.check (32 >> 2)
autoTester.check (1 | 4)
autoTester.check (11 ^ 13)
autoTester.check (12 & 20)
a = 32
a <<= 2
autoTester.check (a)
class A:
def __init__ (self):
self.b = {}
a = A ()
a.b ['c'] = 'd'
__pragma__('opov')
a.b ['c'] += 'e'
__pragma__('noopov')
autoTester.check (a.b ['c'])
4.35. Properties¶
class A:
p = 1234
def getX (self):
return self._x
def setX (self, value):
self._x = value
def getY (self):
return self._y
def setY (self, value):
self._y = 1000 + value # Weird but should be possible
def getY2 (self):
return self._y
def setY2 (self, value):
self._y = value
def getT (self):
return self._t
def setT (self, value):
self._t = value
def getU (self):
return self._u + 10000
def setU (self, value):
self._u = value - 5000
x, y, y2 = property (getX, setX), property (getY, setY), property (getY2, setY2)
t = property (getT, setT)
u = property (getU, setU)
A.q = 5678
class B:
def getZ (self):
return self.z_
def setZ (self, value):
self.z_ = value
z = property (getZ, setZ)
class C:
def __init__ (self):
self.offset = 1234
def getW (self):
return self.w_ + self.offset
def setW (self, value):
self.w_ = value - self.offset
w = property (getW, setW)
def run (autoTester):
a1 = A ()
a2 = A ()
a1.y2 = 1000
a2.y2 = 2000
a1.x = 5
a1.y = 6
a2.x = 7
a2.y = 8
a1.t = 77
a1.u = 88
autoTester.check (a1.x, a1.y, a1.y2)
autoTester.check (a2.x, a2.y, a2.y2)
autoTester.check (a1.p, a2.p, a1.q, a2.q)
autoTester.check (a1.t, a1.u)
b = B ()
c = C ()
b.z = 100100
c.z = 200200
c.w = 300300
autoTester.check (a1.x, b.z, c.z, c.w)
c.w = 400400
c.z = 500500
b.z = 600600
autoTester.check (a1.x, b.z, c.z, c.w)
4.36. Representation as text: the repr and str built-in functions¶
def run(test):
""" Test the repr and string implementations
"""
v = 1
test.check( repr(v) )
test.check( str(v) )
v = "asdf"
test.check( repr(v) )
test.check( str(v) )
v = True
test.check( repr(v) )
test.check( str(v) )
v = False
test.check( repr(v) )
test.check( str(v) )
v = 1.2
test.check( repr(v) )
test.check( str(v) )
v = -31.2
test.check( repr(v) )
test.check( str(v) )
v = 63e-12
test.check( repr(v) )
test.check( str(v) )
v = 24e37
test.check( repr(v) )
test.check( str(v) )
v = -34e-23
test.check( repr(v) )
test.check( str(v) )
v = -89e32
test.check( repr(v) )
test.check( str(v) )
v = None
test.check( repr(v) )
test.check( str(v) )
v = [None]
test.check( repr(v) )
test.check( str(v) )
v = [None, None]
test.check( repr(v) )
test.check( str(v) )
v = [None, 1.02]
test.check( repr(v) )
test.check( str(v) )
v = [1,3.000234]
test.check( repr(v) )
test.check( str(v) )
v = [1,2,3]
test.check( repr(v) )
test.check( str(v) )
v = [1.04, 2.03, 3.005]
test.check( repr(v) )
test.check( str(v) )
v = ["asdf", 2.00009, "1234"]
test.check( repr(v) )
test.check( str(v) )
v = set([1,2,3])
test.check( repr(v) )
test.check( str(v) )
v = set([])
test.check( repr(v) )
test.check( str(v) )
v = (1,2)
test.check( repr(v) )
test.check( str(v) )
v = (3.4, 4.4)
test.check( repr(v) )
test.check( str(v) )
v = (None, 5.32)
test.check( repr(v) )
test.check( str(v) )
v = {}
test.check( repr(v) )
test.check( str(v) )
v = { "a": 1 }
test.check( repr(v) )
test.check( str(v) )
# @note - in python the dictionary key
# ordering is not specified. So the following tests
# cannot be reliably completed when there are more than
# one key in a dict - so this test coverage was skipped for now.
d = { "asdf": 3.4 }
test.check( repr( d ) )
test.check( str( d ) )
d = { "qwer": "qwerqwer qwerqwer" }
test.check( repr( d ) )
test.check( str( d ) )
d = { "a9342" : None }
test.check( repr( d ) )
test.check( str( d ) )
d = { "nfdns" : True }
test.check( repr( d ) )
test.check( str( d ) )
d = { "alel;e;" : False }
test.check( repr( d ) )
test.check( str( d ) )
d = { "didi" : [True,False,True] }
test.check( repr( d ) )
test.check( str( d ) )
d = { "bibi" : [1,2,3] }
test.check( repr( d ) )
test.check( str( d ) )
d = { "gigi" : ["Asdf","qwer","rewer"] }
test.check( repr( d ) )
test.check( str( d ) )
d = { "hihi" : ("esdf","qwer","rewer") }
test.check( repr( d ) )
test.check( str( d ) )
d = { "jiji" : [None, None, None] }
test.check( repr( d ) )
test.check( str( d ) )
d = { "jiji" : (1.3, 3.4) }
test.check( repr( d ) )
test.check( str( d ) )
d = { "jiji" : { "c" : 4 } }
test.check( repr( d ) )
test.check( str( d ) )
class Test1(object):
def __init__(self, val):
self._val = val
def __str__(self):
return("[Test1 {}]".format(self._val))
def __repr__(self):
return(str(self))
class Test2(object):
def __init__(self, val):
self._val = val
def __repr__(self):
return("[Test2 {},{}]".format(self._val, self._val*2))
def __str__(self):
return( repr(self) )
class Test3(Test2):
def __str__(self):
return("[Test3 {}]".format(self._val))
class Test4(object):
def __init__(self, val):
self._val = val
def __repr__(self):
return("[Test4 {}]".format(self._val))
t1 = Test1(2)
test.check( repr(t1) )
test.check( str(t1) )
t1 = Test1(4.5)
test.check( repr(t1) )
test.check( str(t1) )
t1 = Test1("blarg")
test.check( repr(t1) )
test.check( str(t1) )
t1 = Test1([1,2,3])
test.check( repr(t1) )
test.check( str(t1) )
t2 = Test2(3)
test.check( repr(t2) )
test.check( str(t2) )
t2 = Test2(7.6)
test.check( repr(t2) )
test.check( str(t2) )
t2 = Test2(-8.9)
test.check( repr(t2) )
test.check( str(t2) )
t3 = Test3(8)
test.check( repr(t3) )
test.check( str(t3) )
t3 = Test3(3.4)
test.check( repr(t3) )
test.check( str(t3) )
test.check( repr( [t1,t2,3] ) )
d = { "irew" : t1 }
test.check( repr( d ) )
test.check( str( d ) )
d = { "irew" : [t1,t2,t3] }
test.check( repr( d ) )
test.check( str( d ) )
t4 = Test4("qwer")
test.check( repr(t4) )
test.check( str(t4) )
4.37. Set comprehensions¶
def run (autoTester):
even = {2 * i for i in [0, 9, 1, 7, 2, 8, 3, 6, 4, 5]}
autoTester.check (even)
odd = {2 * i + 1 for i in [5, 6, 7, 8, 9, 4, 3, 1, 2, 0]}
autoTester.check (odd)
even.add (12)
even.add (12)
autoTester.check (even)
even.discard (12)
even.discard (12)
autoTester.check (even)
uni = even.union (odd)
autoTester.check (uni)
autoTester.check (odd.isdisjoint (even))
autoTester.check (uni.isdisjoint (even))
autoTester.check (even.issuperset (uni))
autoTester.check (uni.issuperset (even))
autoTester.check (even.issubset (uni))
autoTester.check (uni.issubset (even))
first = {4, 1, 0, 5, 3, 2, 6}
autoTester.check (first)
second = {3, 5, 6, 9, 4, 7, 8}
autoTester.check (second)
inter = first.intersection (second)
autoTester.check (inter)
diff = first.difference (second)
autoTester.check (diff)
symDiff = first.symmetric_difference (second)
autoTester.check (symDiff)
aSet = {200, 4, 5, 100}
aSet.update (first, symDiff, second)
autoTester.check (aSet)
4.38. Super¶
The super () builtin function is supported for cases where there's exactly one path upwards to exactly one matching method. This covers most use cases, even in a diamond class hierarchy, and results in fast and compact code. In case of more than one path, possibly to more than one matching method, use explicit class names, as shown in the example below.
def run (autoTester):
def show (*args):
autoTester.check (*args)
# print (*args) # Leave in for debugging purposes
class R:
def __init__ (self, a, b):
self.a = a
self.b = b
class A (R):
def __init__ (self, a, b, c):
super () .__init__ (a, b)
self.c = c
def f (self, x, y):
show ('A.f:', x, y, self.a, self.b, self.c)
def g (self, x, y):
show ('A.g:', x, y)
class B (R):
def __init__ (self, a, b, d):
super () .__init__ (a, b)
self.d = d
def f (self, x, y):
show ('B.f:', x, y, self.a, self.b, self.d)
def h (self, x, y):
show ('A.h:', x, y, self.a, self.b, self.d)
class C (A):
def __init__ (self, a, b, c):
super () .__init__ (a, b, c)
def f (self, x, y):
super () .f (x, y)
show ('C.f:', x, y, self.a, self.b, self.c)
class D (B):
def __init__ (self, a, b, d):
super () .__init__ (a, b, d)
def f (self, x, y):
super () .f (x, y)
show ('D.f:', x, y, self.a, self.b, self.d)
# Diamond inheritance, use super () only to call exactly one target method via unique path.
# In case of multiple target methods or multiple paths, don't use super (), but refer to ancestor classes explicitly instead
class E (C, D):
def __init__ (self, a, b, c, d):
R.__init__ (self, a, b) # Inherited via multiple legs of a diamond, so call explicitly
self.c = c # Could also have used C.__init__, but symmetry preferred
self.d = d # Don't use both C.__init__ and D.__init__, since R.__init__ will be called by both
# That's harmless here, but not always
def f (self, x, y):
C.f (self, x, y) # Ambiguous part of diamond, don't use super ()
D.f (self, x, y) # Ambiguous part of diamond, don't use super ()
show ('E.f:', x, y, self.a, self.b, self.c, self.d)
def g (self, x, y):
super () .g (x, y) # Unique, using super () is OK
show ('E.g:', x, y, self.a, self.b, self.c, self.d)
def h (self, x, y):
super () .h (x, y) # Unique, using super () is OK
show ('E.h:', x, y, self.a, self.b, self.c, self.d)
rr = R (100, 200)
show ('--1--')
a = A (101, 201, 301)
a.f (711, 811)
a.g (721, 821)
show ('--2--')
b = B (102, 202, 302)
b.f (712, 812)
b.h (732, 832)
show ('--3--')
c = C (103, 203, 303)
c.f (713, 813)
c.g (723, 823)
show ('--4--')
d = D (104, 204, 304)
d.f (714, 814)
d.h (734, 834)
show ('--5--')
e = E (105, 205, 305, 405)
e.f (715, 815)
e.g (725, 825)
e.h (735, 835)
4.39. Simple and augmented assignment¶
class A:
def __init__ (self):
self.i = 0
def f (self):
return self.i
a = A ()
def run (autoTester):
x = 3
y = 5
z = x + y
autoTester.check (z)
l = [1, 2, 3]
l [1] = l [2]
autoTester.check (l)
# Should generate x++
x += 1
autoTester.check (x)
x += +1
autoTester.check (x)
x -= -1
autoTester.check (x)
# Should generate y--
y -= 1
autoTester.check (y)
y -= +1
autoTester.check (y)
y += -1
autoTester.check (y)
x += -3
autoTester.check (x)
x += 6
autoTester.check (x)
y -= 3
autoTester.check (y)
l [1] += l [1]
autoTester.check (l)
x += y
y += x
autoTester.check (x, y)
f = a.f
a.i += 1
autoTester.check (f ())
a.i += 10
autoTester.check (f ())
a.i += a.i
autoTester.check (f ())
4.40. Truthyness: optional Python-style evaluation of truthyness, falsyness and non-empty container selection¶
from org.transcrypt.stubs.browser import __pragma__
__pragma__ ('tconv')
def run (autoTester):
autoTester.check (len ({1:2}))
autoTester.check ('Select nonemtpy container, if any<br>')
autoTester.check ((0) or (1, 2, 3))
autoTester.check (() or (1, 2, 3))
autoTester.check (() or ())
autoTester.check ((-1) or (0) or (1, 2, 3))
autoTester.check (() or (0) or (1, 2, 3))
autoTester.check (() or () or (1, 2, 3))
autoTester.check (() or () or ())
autoTester.check ([0] or [1, 2, 3])
autoTester.check ([] or [1, 2, 3])
autoTester.check ([] or [])
autoTester.check ([-1] or [0] or [1, 2, 3])
autoTester.check ([] or [0] or [1, 2, 3])
autoTester.check ([] or [] or [1, 2, 3])
autoTester.check ([] or [] or [])
autoTester.check ({0} or {1, 2, 3, 4})
autoTester.check (set () or {1, 2, 3, 4})
autoTester.check (set () or set ())
autoTester.check ({-1} or {0} or {1, 2, 3, 5})
autoTester.check (set () or {0} or {1, 2, 3, 6})
autoTester.check (set () or set () or {1, 2, 3, 7})
autoTester.check (set () or set () or set ())
autoTester.check ({0:10} or {1:11, 2:12, 3:13})
autoTester.check ({} or {1, 2, 3, 8})
autoTester.check ({} or {})
autoTester.check ({-1:-11} or {0:10} or {1:11, 2:12, 3:13})
autoTester.check ({} or {0:10} or {1:11, 2:12, 3:13})
autoTester.check ({} or {} or {1:11, 2:12, 3:13})
autoTester.check ({} or {} or {})
autoTester.check ('<br><br>')
autoTester.check ('Boolean evaluations')
for expression in (
'<br> -- falsy -- <br>',
(),
[],
set (),
{},
0,
'',
3 > 5,
False,
'<br> -- truthy -- <br>',
(1, 2, 3),
[1, 2, 3],
{1, 2, 3},
{'a': 1, 'b': 2, 'c': 3},
3,
'hello',
5 > 3,
True
):
if expression in ('<br> -- falsy -- <br>', '<br> -- truthy -- <br>'):
autoTester.check (expression)
else:
autoTester.check (expression, ' . . . ')
autoTester.check ('operators')
autoTester.check (not not expression)
autoTester.check (not not (True and expression))
autoTester.check (not not (False or expression))
autoTester.check (not not (expression and True))
autoTester.check (not not (expression and False))
autoTester.check ('if')
if expression:
autoTester.check (True)
else:
autoTester.check (False)
if expression or expression:
autoTester.check (True)
else:
autoTester.check (False)
if False:
autoTester.check ('if')
elif expression:
autoTester.check ('elif')
else:
autoTester.check ('else')
autoTester.check ('while')
while expression:
autoTester.check (True)
break
autoTester.check ('condex')
autoTester.check (True if expression else False)
if (0.0):
autoTester.check ('0.0')
elif (0.1):
autoTester.check ('0.1')
else:
autoTester.check ('Shouldn\'t be here...')
class A:
pass
class B:
def __bool__ ( self):
return False
class C:
def __bool__ (self):
return True
def __len__ (self):
return 0
class D:
def __len__ (self):
return 0
class E:
def __len__ (self):
return 1
autoTester.check ('instances of custom classes')
autoTester.check (not not A ())
autoTester.check (not not B ())
autoTester.check (not not C ())
autoTester.check (not not D ())
autoTester.check (not not E ())
4.41. Tuple assignment: recursive and in for-headers using enumerate¶
def run (autoTester):
((a, b), santa, [c, d], e) = ((1, 2), 'santa-claus', {3, 4}, 5)
autoTester.check (a, b, c, d, e, santa)
for i, x in enumerate ((0.5, 1.5, 2.5, 3.5)):
autoTester.check (i, x)
e, pi = 3.14, 2.74
e, pi = pi, e
autoTester.check (e, pi)
def f ():
return [(i, 2 * i) for i in range (7000, 10000, 1000)]
def g ():
return f
[k, l], [m, n], (o, p) = g () ()
autoTester.check (k, l, m, n, o, p)