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# -*- coding: utf-8 -*- 

 

u'''Iterators with options. 

 

Iterator classes L{LatLon2PsxyIter} and L{PointsIter} to iterate 

over iterables, lists, sets, tuples, etc. with optional loop-back to 

the initial items, skipping of duplicate items and copying of the 

iterated items. 

''' 

 

from pygeodesy.basics import issubclassof, len2, map2 

from pygeodesy.errors import _IndexError, LenError, PointsError, \ 

_ValueError 

from pygeodesy.interns import NN, _few_, _points_, _too_, _0_, _1_0 

from pygeodesy.lazily import _ALL_LAZY, _ALL_DOCS 

from pygeodesy.named import _Named 

from pygeodesy.namedTuples import Point3Tuple, Points2Tuple 

from pygeodesy.props import property_RO 

from pygeodesy.streprs import Fmt 

from pygeodesy.units import Int, Radius 

from pygeodesy.utily import degrees2m, wrap90, wrap180 

 

__all__ = _ALL_LAZY.iters 

__version__ = '21.06.15' 

 

_items_ = 'items' 

_iterNumpy2len = 1 # adjustable for testing purposes 

_NOTHING = object() # unique 

 

 

class _BaseIter(_Named): 

'''(INTERNAL) Iterator over items with loop-back and de-duplication. 

 

@see: Luciano Ramalho, "Fluent Python", page 418+, O'Reilly, 2016. 

''' 

_closed = True 

_copies = () 

_dedup = False 

_Error = LenError 

_items = None 

_loop = () 

_name = _items_ 

_prev = _NOTHING 

 

def __init__(self, items, loop=0, dedup=False, Error=None, name=NN): 

'''New iterator over an iterable of B{C{items}}. 

 

@arg items: Iterable (any C{type}). 

@kwarg loop: Number of loop-back items, also initial enumerate 

and iterate index (non-negative C{int}). 

@kwarg dedup: Skip duplicate items (C{bool}). 

@kwarg Error: Error to raise (L{LenError}). 

@kwarg name: Optional name (C{str}). 

 

@raise Error: Insufficient number of B{C{items}}. 

''' 

if dedup: 

self._dedup = True 

if issubclassof(Error, Exception): 

self._Error = Error 

if name: 

self.rename(name) 

 

if isinstance(items, (list, tuple)): # range in Python 2 

self._items = items 

# XXX if hasattr(items, 'next') or hasattr(items, '__length_hint__'): 

# XXX # handle reversed, iter, etc. items types 

self._iter = iter(items) 

self._indx = -1 

if Int(loop) > 0: 

try: 

self._loop = tuple(self.next for _ in range(loop)) 

if self.loop != loop: 

raise RuntimeError # force Error 

except (RuntimeError, StopIteration): 

raise self._Error(self.name, self.loop, txt=_too_(_few_)) 

 

@property_RO 

def copies(self): 

'''Get the saved copies, if any (C{tuple} or C{list}) and only I{once}. 

''' 

cs = self._copies 

if cs: 

self._copies = () 

return cs 

 

@property_RO 

def dedup(self): 

'''Get the de-duplication setting (C{bool}). 

''' 

return self._dedup 

 

def enumerate(self, closed=False, copies=False, dedup=False): 

'''Yield all items, each as a 2-tuple C{(index, item)}. 

 

@kwarg closed: Look back to the first B{C{point(s)}}. 

@kwarg copies: Make a copy of all B{C{items}} (C{bool}). 

@kwarg dedup: Set de-duplication in loop-back (C{bool}). 

''' 

for item in self.iterate(closed=closed, copies=copies, dedup=dedup): 

yield self._indx, item 

 

def __getitem__(self, index): 

'''Get the item(s) at the given B{C{index}} or C{slice}. 

 

@raise IndexError: Invalid B{C{index}}, beyond B{C{loop}}. 

''' 

t = self._items or self._copies or self._loop 

try: # Luciano Ramalho, "Fluent Python", page 293+, O'Reilly, 2016. 

if isinstance(index, slice): 

return t[index.start:index.stop:index.step] 

else: 

return t[index] 

except IndexError as x: 

t = Fmt.SQUARE(self.name, index) 

raise _IndexError(str(x), txt=t) 

 

def __iter__(self): # PYCHOK no cover 

'''Make this iterator C{iterable}. 

''' 

# Luciano Ramalho, "Fluent Python", page 421, O'Reilly, 2016. 

return self.iterate() # XXX or self? 

 

def iterate(self, closed=False, copies=False, dedup=False): 

'''Yield all items, each as C{item}. 

 

@kwarg closed: Look back to the first B{C{point(s)}}. 

@kwarg copies: Make a copy of all B{C{items}} (C{bool}). 

@kwarg dedup: Set de-duplication in loop-back (C{bool}). 

 

@raise Error: Using C{B{closed}=True} without B{C{loop}}-back. 

''' 

if closed and not self.loop: 

raise self._Error(closed=closed, loop=self.loop) 

 

if copies: 

if self._items: 

self._copies = self._items 

self._items = copy_ = None 

else: 

self._copies = list(self._loop) 

copy_ = self._copies.append 

else: # del B{C{items}} reference 

self._items = copy_ = None 

 

self._closed = closed 

if self._iter: 

try: 

next_ = self.next_ 

if copy_: 

while True: 

item = next_(dedup=dedup) 

copy_(item) 

yield item 

else: 

while True: 

yield next_(dedup=dedup) 

except StopIteration: 

self._iter = () # del self._iter, prevent re-iterate 

 

@property_RO 

def loop(self): 

'''Get the B{C{loop}} setting (C{int}), C{0} for non-loop-back. 

''' 

return len(self._loop) 

 

@property_RO 

def next(self): 

'''Get the next item. 

''' 

return self._next_dedup() if self._dedup else self._next(False) 

 

# __next__ # NO __next__ AND __iter__ ... see Ramalho, page 426 

 

def next_(self, dedup=False): 

'''Return the next item. 

 

@kwarg dedup: Set de-duplication for loop-back (C{bool}). 

''' 

return self._next_dedup() if self._dedup else self._next(dedup) 

 

def _next(self, dedup): 

'''Return the next item, regardless. 

 

@arg dedup: Set de-duplication for loop-back (C{bool}). 

''' 

try: 

self._indx += 1 

self._prev = item = next(self._iter) 

return item 

except StopIteration: 

pass 

if self._closed and self._loop: # loop back 

self._dedup = bool(dedup or self._dedup) 

self._indx = 0 

self._iter = iter(self._loop) 

self._loop = () 

return next(self._iter) 

 

def _next_dedup(self): 

'''Return the next item, different from the previous one. 

''' 

prev = self._prev 

item = self._next(True) 

if prev is not _NOTHING: 

while item == prev: 

item = self._next(True) 

return item 

 

 

class PointsIter(_BaseIter): 

'''Iterator for C{points} with optional loop-back and copies. 

''' 

_base = None 

_Error = PointsError 

 

def __init__(self, points, loop=0, base=None, dedup=False, name=NN): 

'''New L{PointsIter} iterator. 

 

@arg points: C{Iterable} or C{list}, C{sequence}, C{set}, C{tuple}, 

etc. (C{point}s). 

@kwarg loop: Number of loop-back points, also initial C{enumerate} 

and C{iterate} index (non-negative C{int}). 

@kwarg base: Optional B{C{points}} instance for type checking (C{any}). 

@kwarg dedup: Skip duplicate points (C{bool}). 

@kwarg name: Optional name (C{str}). 

 

@raise PointsError: Insufficient number of B{C{points}}. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}. 

''' 

_BaseIter.__init__(self, points, loop=loop, dedup=dedup, name=name or _points_) 

 

if base and not (isNumpy2(points) or isTuple2(points)): 

self._base = base 

 

def enumerate(self, closed=False, copies=False): # PYCHOK signature 

'''Iterate and yield each point as a 2-tuple C{(index, point)}. 

 

@kwarg closed: Look back to the first B{C{point(s)}}, de-dup'ed (C{bool}). 

@kwarg copies: Save a copy of all B{C{points}} (C{bool}). 

 

@raise PointsError: Insufficient number of B{C{points}} or using 

C{B{closed}=True} without B{C{loop}}-back. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}-compatible. 

''' 

for p in self.iterate(closed=closed, copies=copies): 

yield self._indx, p 

 

def iterate(self, closed=False, copies=False): # PYCHOK signature 

'''Iterate through all B{C{points}} starting at index C{loop}. 

 

@kwarg closed: Look back to the first B{C{point(s)}}, de-dup'ed (C{bool}). 

@kwarg copies: Save a copy of all B{C{points}} (C{bool}). 

 

@raise PointsError: Insufficient number of B{C{points}} or using 

C{B{closed}=True} without B{C{loop}}-back. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}-compatible. 

''' 

if self._base: 

base_ = self._base.others 

fmt_ = Fmt.SQUARE(points=0).replace 

else: 

base_ = fmt_ = None 

 

n = self.loop if self._iter else 0 

for p in _BaseIter.iterate(self, closed=closed, copies=copies, dedup=closed): 

if base_: 

base_(p, name=fmt_(_0_, str(self._indx)), up=2) 

yield p 

n += 1 

if n < (4 if closed else 2): 

raise self._Error(self.name, n, txt=_too_(_few_)) 

 

 

class LatLon2PsxyIter(PointsIter): 

'''Iterate and convert for C{points} with optional loop-back and copies. 

''' 

_deg2m = None 

_radius = None # keep degrees 

_wrap = True 

 

def __init__(self, points, loop=0, base=None, wrap=True, radius=None, 

dedup=False, name=NN): 

'''New L{LatLon2PsxyIter} iterator. 

 

@note: The C{LatLon} latitude is considered the I{pseudo-y} and 

longitude the I{pseudo-x} coordinate, like L{LatLon2psxy}. 

 

@arg points: C{Iterable} or C{list}, C{sequence}, C{set}, C{tuple}, 

etc. (C{LatLon}[]). 

@kwarg loop: Number of loop-back points, also initial C{enumerate} 

and C{iterate} index (non-negative C{int}). 

@kwarg base: Optional B{C{points}} instance for type checking (C{any}). 

@kwarg wrap: Wrap lat- and longitudes (C{bool}). 

@kwarg radius: Mean earth radius (C{meter}) for conversion from 

C{degrees} to C{meter} (or C{radians} if C{B{radius}=1}). 

@kwarg dedup: Skip duplicate points (C{bool}). 

@kwarg name: Optional name (C{str}). 

 

@raise PointsError: Insufficient number of B{C{points}}. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}-compatible. 

''' 

PointsIter.__init__(self, points, loop=loop, base=base, dedup=dedup, name=name) 

if not wrap: 

self._wrap = False 

if radius: 

self._radius = r = Radius(radius) 

self._deg2m = degrees2m(_1_0, r) 

 

def __getitem__(self, index): 

'''Get the point(s) at the given B{C{index}} or C{slice}. 

 

@raise IndexError: Invalid B{C{index}}, beyond B{C{loop}}. 

''' 

ll = PointsIter.__getitem__(self, index) 

if isinstance(index, slice): 

return map2(self._point3Tuple, ll) 

else: 

return self._point3Tuple(ll) 

 

def enumerate(self, closed=False, copies=False): # PYCHOK signature 

'''Iterate and yield each point as a 2-tuple C{(index, L{Point3Tuple})}. 

 

@kwarg closed: Look back to the first B{C{point(s)}}, de-dup'ed (C{bool}). 

@kwarg copies: Save a copy of all B{C{points}} (C{bool}). 

 

@raise PointsError: Insufficient number of B{C{points}} or using 

C{B{closed}=True} without B{C{loop}}-back. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}-compatible. 

''' 

return PointsIter.enumerate(self, closed=closed, copies=copies) 

 

def iterate(self, closed=False, copies=False): # PYCHOK signature 

'''Iterate the B{C{points}} starting at index B{C{loop}} and 

yield each as a L{Point3Tuple}C{(x, y, ll)}. 

 

@kwarg closed: Loop back to the first B{C{point(s)}}, de-dup'ed (C{bool}). 

@kwarg copies: Save a copy of all B{C{points}} (C{bool}). 

 

@raise PointsError: Insufficient number of B{C{points}} or using 

C{B{closed}=True} without B{C{loop}}-back. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}}-compatible. 

''' 

if self._deg2m not in (None, _1_0): 

_point3Tuple = self._point3Tuple 

elif self._wrap: 

def _point3Tuple(ll): 

return Point3Tuple(wrap180(ll.lon), wrap90(ll.lat), ll) 

else: 

def _point3Tuple(ll): # PYCHOK redef 

return Point3Tuple(ll.lon, ll.lat, ll) 

 

for ll in PointsIter.iterate(self, closed=closed, copies=copies): 

yield _point3Tuple(ll) 

 

def _point3Tuple(self, ll): 

'''(INTERNAL) Create a L{Point3Tuple} for point B{C{ll}}. 

''' 

x, y = ll.lon, ll.lat # note, x, y = lon, lat 

if self._wrap: 

x, y = wrap180(x), wrap90(y) 

d = self._deg2m 

if d: # convert degrees 

x *= d 

y *= d 

return Point3Tuple(x, y, ll) 

 

 

def _imdex2(closed, n): # PYCHOK by .clipy 

'''(INTERNAL) Return first and second index of C{range(B{n})}. 

''' 

return (n-1, 0) if closed else (0, 1) 

 

 

def isNumpy2(obj): 

'''Check for an B{C{Numpy2LatLon}} points wrapper. 

 

@arg obj: The object (any C{type}). 

 

@return: C{True} if B{C{obj}} is an B{C{Numpy2LatLon}} 

instance, C{False} otherwise. 

''' 

# isinstance(self, (Numpy2LatLon, ...)) 

return getattr(obj, isNumpy2.__name__, False) 

 

 

def isPoints2(obj): 

'''Check for an B{C{LatLon2psxy}} points wrapper. 

 

@arg obj: The object (any C{type}). 

 

@return: C{True} if B{C{obj}} is an B{C{LatLon2psxy}} 

instance, C{False} otherwise. 

''' 

# isinstance(self, (LatLon2psxy, ...)) 

return getattr(obj, isPoints2.__name__, False) 

 

 

def isTuple2(obj): 

'''Check for an B{C{Tuple2LatLon}} points wrapper. 

 

@arg obj: The object (any). 

 

@return: C{True} if B{C{obj}} is an B{C{Tuple2LatLon}} 

instance, C{False} otherwise. 

''' 

# isinstance(self, (Tuple2LatLon, ...)) 

return getattr(obj, isTuple2.__name__, False) 

 

 

def iterNumpy2(obj): 

'''Iterate over Numpy2 wrappers or other sequences exceeding 

the threshold. 

 

@arg obj: Points array, list, sequence, set, etc. (any). 

 

@return: C{True} do, C{False} don't iterate. 

''' 

try: 

return isNumpy2(obj) or len(obj) > _iterNumpy2len 

except TypeError: 

return False 

 

 

def iterNumpy2over(n=None): 

'''Get or set the L{iterNumpy2} threshold. 

 

@kwarg n: Optional, new threshold (C{int}). 

 

@return: Previous threshold (C{int}). 

 

@raise ValueError: Invalid B{C{n}}. 

''' 

global _iterNumpy2len 

p = _iterNumpy2len 

if n is not None: 

try: 

i = int(n) 

if i > 0: 

_iterNumpy2len = i 

else: 

raise ValueError 

except (TypeError, ValueError): 

raise _ValueError(n=n) 

return p 

 

 

def points2(points, closed=True, base=None, Error=PointsError): 

'''Check a path or polygon represented by points. 

 

@arg points: The path or polygon points (C{LatLon}[]) 

@kwarg closed: Optionally, consider the polygon closed, 

ignoring any duplicate or closing final 

B{C{points}} (C{bool}). 

@kwarg base: Optionally, check all B{C{points}} against 

this base class, if C{None} don't check. 

@kwarg Error: Exception to raise (C{ValueError}). 

 

@return: A L{Points2Tuple}C{(number, points)} with the number 

of points and the points C{list} or C{tuple}. 

 

@raise PointsError: Insufficient number of B{C{points}}. 

 

@raise TypeError: Some B{C{points}} are not B{C{base}} 

compatible. 

''' 

n, points = len2(points) 

 

if closed: 

# remove duplicate or closing final points 

while n > 1 and points[n-1] in (points[0], points[n-2]): 

n -= 1 

# XXX following line is unneeded if points 

# are always indexed as ... i in range(n) 

points = points[:n] # XXX numpy.array slice is a view! 

 

if n < (3 if closed else 1): 

raise Error(points=n, txt=_too_(_few_)) 

 

if base and not (isNumpy2(points) or isTuple2(points)): 

for i in range(n): 

base.others(points[i], name=Fmt.SQUARE(points=i)) 

 

return Points2Tuple(n, points) 

 

 

__all__ += _ALL_DOCS(_BaseIter) 

 

# **) MIT License 

# 

# Copyright (C) 2016-2021 -- mrJean1 at Gmail -- All Rights Reserved. 

# 

# Permission is hereby granted, free of charge, to any person obtaining a 

# copy of this software and associated documentation files (the "Software"), 

# to deal in the Software without restriction, including without limitation 

# the rights to use, copy, modify, merge, publish, distribute, sublicense, 

# and/or sell copies of the Software, and to permit persons to whom the 

# Software is furnished to do so, subject to the following conditions: 

# 

# The above copyright notice and this permission notice shall be included 

# in all copies or substantial portions of the Software. 

# 

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 

# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 

# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 

# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 

# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 

# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 

# OTHER DEALINGS IN THE SOFTWARE.