Coverage for pygeodesy/basics.py: 91%
262 statements
« prev ^ index » next coverage.py v7.6.1, created at 2025-01-06 12:20 -0500
« prev ^ index » next coverage.py v7.6.1, created at 2025-01-06 12:20 -0500
2# -*- coding: utf-8 -*-
4u'''Some, basic definitions, functions and dependencies.
6Use env variable C{PYGEODESY_XPACKAGES} to avoid import of dependencies
7C{geographiclib}, C{numpy} and/or C{scipy}. Set C{PYGEODESY_XPACKAGES}
8to a comma-separated list of package names to be excluded from import.
9'''
10# make sure int/int division yields float quotient
11from __future__ import division
12division = 1 / 2 # .albers, .azimuthal, .constants, etc., .utily
13if not division:
14 raise ImportError('%s 1/2 == %s' % ('division', division))
15del division
17# from pygeodesy.cartesianBase import CartesianBase # _MODS
18# from pygeodesy.constants import isneg0, NEG0 # _MODS
19from pygeodesy.errors import _AttributeError, _ImportError, _NotImplementedError, \
20 _TypeError, _TypesError, _ValueError, _xAssertionError, \
21 _xkwds_get1
22# from pygeodesy.fsums import _isFsum_2Tuple # _MODS
23from pygeodesy.internals import _0_0, _enquote, _getenv, _passarg, _PYGEODESY, \
24 _version_info
25from pygeodesy.interns import MISSING, NN, _1_, _by_, _COMMA_, _DOT_, _DEPRECATED_, \
26 _ELLIPSIS4_, _EQUAL_, _in_, _invalid_, _N_A_, _not_, \
27 _not_scalar_, _odd_, _SPACE_, _UNDER_, _version_
28# from pygeodesy.latlonBase import LatLonBase # _MODS
29from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS, LazyImportError
30# from pygeodesy.named import classname, modulename, _name__ # _MODS
31# from pygeodesy.nvectorBase import NvectorBase # _MODS
32# from pygeodesy.props import _update_all # _MODS
33# from pygeodesy.streprs import Fmt # _MODS
35from copy import copy as _copy, deepcopy as _deepcopy
36from math import copysign as _copysign
37# import inspect as _inspect # _MODS
39__all__ = _ALL_LAZY.basics
40__version__ = '24.12.31'
42_below_ = 'below'
43_list_tuple_types = (list, tuple)
44_required_ = 'required'
46try: # Luciano Ramalho, "Fluent Python", O'Reilly, 2016 p. 395, 2022 p. 577+
47 from numbers import Integral as _Ints, Real as _Scalars # .units
48except ImportError:
49 try:
50 _Ints = int, long # int objects (C{tuple})
51 except NameError: # Python 3+
52 _Ints = int, # int objects (C{tuple})
53 _Scalars = (float,) + _Ints
55try:
56 try: # use C{from collections.abc import ...} in Python 3.9+
57 from collections.abc import Sequence as _Sequence # in .points
58 except ImportError: # no .abc in Python 3.8- and 2.7-
59 from collections import Sequence as _Sequence # in .points
60 if isinstance([], _Sequence) and isinstance((), _Sequence):
61 # and isinstance(range(1), _Sequence):
62 _Seqs = _Sequence
63 else:
64 raise ImportError() # _AssertionError
65except ImportError:
66 _Sequence = tuple # immutable for .points._Basequence
67 _Seqs = list, _Sequence # range for function len2 below
69try:
70 _Bytes = unicode, bytearray # PYCHOK in .internals
71 _Strs = basestring, str # XXX str == bytes
72 str2ub = ub2str = _passarg # avoids UnicodeDecodeError
74 def _Xstr(exc): # PYCHOK no cover
75 '''I{Invoke only with caught ImportError} B{C{exc}}.
77 C{... "can't import name _distributor_init" ...}
79 only for C{numpy}, C{scipy} import errors occurring
80 on arm64 Apple Silicon running macOS' Python 2.7.16?
81 '''
82 t = str(exc)
83 if '_distributor_init' in t:
84 from sys import exc_info
85 from traceback import extract_tb
86 tb = exc_info()[2] # 3-tuple (type, value, traceback)
87 t4 = extract_tb(tb, 1)[0] # 4-tuple (file, line, name, 'import ...')
88 t = _SPACE_("can't", t4[3] or _N_A_)
89 del tb, t4
90 return t
92except NameError: # Python 3+
93 from pygeodesy.interns import _utf_8_
95 _Bytes = bytes, bytearray # in .internals
96 _Strs = str, # tuple
97 _Xstr = str
99 def str2ub(sb):
100 '''Convert C{str} to C{unicode bytes}.
101 '''
102 if isinstance(sb, _Strs):
103 sb = sb.encode(_utf_8_)
104 return sb
106 def ub2str(ub):
107 '''Convert C{unicode bytes} to C{str}.
108 '''
109 if isinstance(ub, _Bytes):
110 ub = str(ub.decode(_utf_8_))
111 return ub
114# def _args_kwds_count2(func, exelf=True): # in .formy
115# '''(INTERNAL) Get a C{func}'s args and kwds count as 2-tuple
116# C{(nargs, nkwds)}, including arg C{self} for methods.
117#
118# @kwarg exelf: If C{True}, exclude C{self} in the C{args}
119# of a method (C{bool}).
120# '''
121# i = _MODS.inspect
122# try:
123# a = k = 0
124# for _, p in i.signature(func).parameters.items():
125# if p.kind is p.POSITIONAL_OR_KEYWORD:
126# if p.default is p.empty:
127# a += 1
128# else:
129# k += 1
130# except AttributeError: # Python 2-
131# s = i.getargspec(func)
132# k = len(s.defaults or ())
133# a = len(s.args) - k
134# if exelf and a > 0 and i.ismethod(func):
135# a -= 1
136# return a, k
139def _args_kwds_names(func, splast=False):
140 '''(INTERNAL) Get a C{func}'s args and kwds names, including
141 C{self} for methods.
143 @kwarg splast: If C{True}, split the last keyword argument
144 at UNDERscores (C{bool}).
146 @note: Python 2 may I{not} include the C{*args} nor the
147 C{**kwds} names.
148 '''
149 i = _MODS.inspect
150 try:
151 args_kwds = i.signature(func).parameters.keys()
152 except AttributeError: # Python 2-
153 args_kwds = i.getargspec(func).args
154 if splast and args_kwds: # PYCHOK no cover
155 args_kwds = list(args_kwds)
156 t = args_kwds[-1:]
157 if t:
158 s = t[0].strip(_UNDER_).split(_UNDER_)
159 if len(s) > 1 or s != t:
160 args_kwds += s
161 return tuple(args_kwds)
164def clips(sb, limit=50, white=NN, length=False):
165 '''Clip a string to the given length limit.
167 @arg sb: String (C{str} or C{bytes}).
168 @kwarg limit: Length limit (C{int}).
169 @kwarg white: Optionally, replace all whitespace (C{str}).
170 @kwarg length: If C{True}, append the original I{[length]} (C{bool}).
172 @return: The clipped or unclipped B{C{sb}}.
173 '''
174 T, n = type(sb), len(sb)
175 if n > limit > 8:
176 h = limit // 2
177 sb = T(_ELLIPSIS4_).join((sb[:h], sb[-h:]))
178 if length:
179 n = _MODS.streprs.Fmt.SQUARE(n)
180 sb = T(NN).join((sb, n))
181 if white: # replace whitespace
182 sb = T(white).join(sb.split())
183 return sb
186def copysign0(x, y):
187 '''Like C{math.copysign(x, y)} except C{zero}, I{unsigned}.
189 @return: C{math.copysign(B{x}, B{y})} if B{C{x}} else
190 C{type(B{x})(0)}.
191 '''
192 return _copysign(x, (y if y else 0)) if x else copytype(0, x)
195def copytype(x, y):
196 '''Return the value of B{x} as C{type} of C{y}.
198 @return: C{type(B{y})(B{x})}.
199 '''
200 return type(y)(x if x else _0_0)
203def _enumereverse(iterable):
204 '''(INTERNAL) Reversed C{enumberate}.
205 '''
206 for j in _reverange(len(iterable)):
207 yield j, iterable[j]
210def halfs2(str2):
211 '''Split a string in 2 halfs.
213 @arg str2: String to split (C{str}).
215 @return: 2-Tuple C{(_1st, _2nd)} half (C{str}).
217 @raise ValueError: Zero or odd C{len(B{str2})}.
218 '''
219 h, r = divmod(len(str2), 2)
220 if r or not h:
221 raise _ValueError(str2=str2, txt=_odd_)
222 return str2[:h], str2[h:]
225def int1s(x): # PYCHOK no cover
226 '''Count the number of 1-bits in an C{int}, I{unsigned}.
228 @note: C{int1s(-B{x}) == int1s(abs(B{x}))}.
229 '''
230 try:
231 return x.bit_count() # Python 3.10+
232 except AttributeError:
233 # bin(-x) = '-' + bin(abs(x))
234 return bin(x).count(_1_)
237def isbool(obj):
238 '''Is B{C{obj}}ect a C{bool}ean?
240 @arg obj: The object (any C{type}).
242 @return: C{True} if C{bool}ean, C{False} otherwise.
243 '''
244 return isinstance(obj, bool) # and (obj is False
245# or obj is True)
247assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2
250def isCartesian(obj, ellipsoidal=None):
251 '''Is B{C{obj}}ect some C{Cartesian}?
253 @arg obj: The object (any C{type}).
254 @kwarg ellipsoidal: If C{None}, return the type of any C{Cartesian},
255 if C{True}, only an ellipsoidal C{Cartesian type}
256 or if C{False}, only a spherical C{Cartesian type}.
258 @return: C{type(B{obj}} if a C{Cartesian} of the required type, C{False}
259 if a C{Cartesian} of an other type or {None} otherwise.
260 '''
261 if ellipsoidal is not None:
262 try:
263 return obj.ellipsoidalCartesian if ellipsoidal else obj.sphericalCartesian
264 except AttributeError:
265 return None
266 return isinstanceof(obj, _MODS.cartesianBase.CartesianBase)
269def isclass(obj): # XXX avoid epydoc Python 2.7 error
270 '''Is B{C{obj}}ect a C{Class} or C{type}?
271 '''
272 return _MODS.inspect.isclass(obj)
275def iscomplex(obj, both=False):
276 '''Is B{C{obj}}ect a C{complex} or complex literal C{str}?
278 @arg obj: The object (any C{type}).
279 @kwarg both: If C{True}, check complex C{str} (C{bool}).
281 @return: C{True} if C{complex}, C{False} otherwise.
282 '''
283 try: # hasattr('conjugate', 'real' and 'imag')
284 return isinstance(obj, complex) or bool(both and isstr(obj) and
285 isinstance(complex(obj), complex)) # numbers.Complex?
286 except (TypeError, ValueError):
287 return False
290def isDEPRECATED(obj):
291 '''Is B{C{obj}}ect a C{DEPRECATED} class, method or function?
293 @return: C{True} if C{DEPRECATED}, {False} if not or
294 C{None} if undetermined.
295 '''
296 try: # XXX inspect.getdoc(obj) or obj.__doc__
297 doc = obj.__doc__.lstrip()
298 return bool(doc and doc.startswith(_DEPRECATED_))
299 except AttributeError:
300 return None
303def isfloat(obj, both=False):
304 '''Is B{C{obj}}ect a C{float} or float literal C{str}?
306 @arg obj: The object (any C{type}).
307 @kwarg both: If C{True}, check float C{str} (C{bool}).
309 @return: C{True} if C{float}, C{False} otherwise.
310 '''
311 try:
312 return isinstance(obj, float) or bool(both and
313 isstr(obj) and isinstance(float(obj), float))
314 except (TypeError, ValueError):
315 return False
318try:
319 isidentifier = str.isidentifier # Python 3, must be str
320except AttributeError: # Python 2-
322 def isidentifier(obj):
323 '''Is B{C{obj}}ect a Python identifier?
324 '''
325 return bool(obj and isstr(obj)
326 and obj.replace(_UNDER_, NN).isalnum()
327 and not obj[:1].isdigit())
330def isinstanceof(obj, *Classes):
331 '''Is B{C{obj}}ect an instance of one of the C{Classes}?
333 @arg obj: The object (any C{type}).
334 @arg Classes: One or more classes (C{Class}).
336 @return: C{type(B{obj}} if one of the B{C{Classes}},
337 C{None} otherwise.
338 '''
339 return type(obj) if isinstance(obj, Classes) else None
342def isint(obj, both=False):
343 '''Is B{C{obj}}ect an C{int} or integer C{float} value?
345 @arg obj: The object (any C{type}).
346 @kwarg both: If C{True}, check C{float} and L{Fsum}
347 type and value (C{bool}).
349 @return: C{True} if C{int} or I{integer} C{float}
350 or L{Fsum}, C{False} otherwise.
352 @note: Both C{isint(True)} and C{isint(False)} return
353 C{False} (and no longer C{True}).
354 '''
355 if isinstance(obj, _Ints):
356 return not isbool(obj)
357 elif both: # and isinstance(obj, (float, Fsum))
358 try: # NOT , _Scalars) to include Fsum!
359 return obj.is_integer()
360 except AttributeError:
361 pass # XXX float(int(obj)) == obj?
362 return False
365def isiterable(obj, strict=False):
366 '''Is B{C{obj}}ect C{iterable}?
368 @arg obj: The object (any C{type}).
369 @kwarg strict: If C{True}, check class attributes (C{bool}).
371 @return: C{True} if C{iterable}, C{False} otherwise.
372 '''
373 # <https://PyPI.org/project/isiterable/>
374 return isiterabletype(obj) if strict else hasattr(obj, '__iter__') # map, range, set
377def isiterablen(obj, strict=False):
378 '''Is B{C{obj}}ect C{iterable} and has C{len}gth?
380 @arg obj: The object (any C{type}).
381 @kwarg strict: If C{True}, check class attributes (C{bool}).
383 @return: C{True} if C{iterable} with C{len}gth, C{False} otherwise.
384 '''
385 _has = isiterabletype if strict else hasattr
386 return _has(obj, '__len__') and _has(obj, '__getitem__')
389def isiterabletype(obj, method='__iter__'):
390 '''Is B{C{obj}}ect an instance of an C{iterable} class or type?
392 @arg obj: The object (any C{type}).
393 @kwarg method: The name of the required method (C{str}).
395 @return: The C{base-class} if C{iterable}, C{None} otherwise.
396 '''
397 try: # <https://StackOverflow.com/questions/73568964>
398 for b in type(obj).__mro__[:-1]: # ignore C{object}
399 try:
400 if callable(b.__dict__[method]):
401 return b
402 except (AttributeError, KeyError):
403 pass
404 except (AttributeError, TypeError):
405 pass
406 return None
409try:
410 from keyword import iskeyword # Python 2.7+
411except ImportError:
413 def iskeyword(unused):
414 '''Not Implemented, C{False} always.
415 '''
416 return False
419def isLatLon(obj, ellipsoidal=None):
420 '''Is B{C{obj}}ect some C{LatLon}?
422 @arg obj: The object (any C{type}).
423 @kwarg ellipsoidal: If C{None}, return the type of any C{LatLon},
424 if C{True}, only an ellipsoidal C{LatLon type}
425 or if C{False}, only a spherical C{LatLon type}.
427 @return: C{type(B{obj}} if a C{LatLon} of the required type, C{False}
428 if a C{LatLon} of an other type or {None} otherwise.
429 '''
430 if ellipsoidal is not None:
431 try:
432 return obj.ellipsoidalLatLon if ellipsoidal else obj.sphericalLatLon
433 except AttributeError:
434 return None
435 return isinstanceof(obj, _MODS.latlonBase.LatLonBase)
438def islistuple(obj, minum=0):
439 '''Is B{C{obj}}ect a C{list} or C{tuple} with non-zero length?
441 @arg obj: The object (any C{type}).
442 @kwarg minum: Minimal C{len} required C({int}).
444 @return: C{True} if a C{list} or C{tuple} with C{len} at
445 least B{C{minum}}, C{False} otherwise.
446 '''
447 return isinstance(obj, _list_tuple_types) and len(obj) >= minum
450def isNvector(obj, ellipsoidal=None):
451 '''Is B{C{obj}}ect some C{Nvector}?
453 @arg obj: The object (any C{type}).
454 @kwarg ellipsoidal: If C{None}, return the type of any C{Nvector},
455 if C{True}, only an ellipsoidal C{Nvector type}
456 or if C{False}, only a spherical C{Nvector type}.
458 @return: C{type(B{obj}} if an C{Nvector} of the required type, C{False}
459 if an C{Nvector} of an other type or {None} otherwise.
460 '''
461 if ellipsoidal is not None:
462 try:
463 return obj.ellipsoidalNvector if ellipsoidal else obj.sphericalNvector
464 except AttributeError:
465 return None
466 return isinstanceof(obj, _MODS.nvectorBase.NvectorBase)
469def isodd(x):
470 '''Is B{C{x}} odd?
472 @arg x: Value (C{scalar}).
474 @return: C{True} if odd, C{False} otherwise.
475 '''
476 return bool(int(x) & 1) # == bool(int(x) % 2)
479def isscalar(obj, both=False):
480 '''Is B{C{obj}}ect an C{int} or integer C{float} value?
482 @arg obj: The object (any C{type}).
483 @kwarg both: If C{True}, check L{Fsum} and L{Fsum2Tuple}
484 residuals.
486 @return: C{True} if C{int}, C{float} or C{Fsum/-2Tuple}
487 with zero residual, C{False} otherwise.
488 '''
489 if isinstance(obj, _Scalars):
490 return not isbool(obj) # exclude bool
491 elif both and _MODS.fsums._isFsum_2Tuple(obj):
492 return bool(obj.residual == 0)
493 return False
496def issequence(obj, *excls):
497 '''Is B{C{obj}}ect some sequence type?
499 @arg obj: The object (any C{type}).
500 @arg excls: Classes to exclude (C{type}), all positional.
502 @note: Excluding C{tuple} implies excluding C{namedtuple}.
504 @return: C{True} if a sequence, C{False} otherwise.
505 '''
506 return isinstance(obj, _Seqs) and not (excls and isinstance(obj, excls))
509def isstr(obj):
510 '''Is B{C{obj}}ect some string type?
512 @arg obj: The object (any C{type}).
514 @return: C{True} if a C{str}, C{bytes}, ...,
515 C{False} otherwise.
516 '''
517 return isinstance(obj, _Strs)
520def issubclassof(Sub, *Supers):
521 '''Is B{C{Sub}} a class and sub-class of some other class(es)?
523 @arg Sub: The sub-class (C{Class}).
524 @arg Supers: One or more C(super) classes (C{Class}).
526 @return: C{True} if a sub-class of any B{C{Supers}}, C{False}
527 if not (C{bool}) or C{None} if not a class or if no
528 B{C{Supers}} are given or none of those are a class.
529 '''
530 if isclass(Sub):
531 t = tuple(S for S in Supers if isclass(S))
532 if t:
533 return bool(issubclass(Sub, t)) # built-in
534 return None
537def itemsorted(adict, *items_args, **asorted_reverse):
538 '''Return the items of C{B{adict}} sorted I{alphabetically,
539 case-insensitively} and in I{ascending} order.
541 @arg items_args: Optional positional argument(s) for method
542 C{B{adict}.items(B*{items_args})}.
543 @kwarg asorted_reverse: Use C{B{asorted}=False} for I{alphabetical,
544 case-sensitive} sorting and C{B{reverse}=True} for
545 sorting in C{descending} order.
546 '''
547 def _ins(item): # functools.cmp_to_key
548 k, v = item
549 return k.lower()
551 def _reverse_key(asorted=True, reverse=False):
552 return dict(reverse=reverse, key=_ins if asorted else None)
554 items = adict.items(*items_args) if items_args else adict.items()
555 return sorted(items, **_reverse_key(**asorted_reverse))
558def len2(items):
559 '''Make built-in function L{len} work for generators, iterators,
560 etc. since those can only be started exactly once.
562 @arg items: Generator, iterator, list, range, tuple, etc.
564 @return: 2-Tuple C{(n, items)} of the number of items (C{int})
565 and the items (C{list} or C{tuple}).
566 '''
567 if not isinstance(items, _Seqs): # NOT hasattr(items, '__len__'):
568 items = list(items)
569 return len(items), items
572def map1(fun1, *xs): # XXX map_
573 '''Call a single-argument function to each B{C{xs}}
574 and return a C{tuple} of results.
576 @arg fun1: 1-Arg function (C{callable}).
577 @arg xs: Arguments (C{any positional}).
579 @return: Function results (C{tuple}).
580 '''
581 return tuple(map(fun1, xs))
584def map2(fun, *xs, **strict):
585 '''Like Python's B{C{map}} but returning a C{tuple} of results.
587 Unlike Python 2's built-in L{map}, Python 3+ L{map} returns a
588 L{map} object, an iterator-like object which generates the
589 results only once. Converting the L{map} object to a tuple
590 maintains the Python 2 behavior.
592 @arg fun: Function (C{callable}).
593 @arg xs: Arguments (C{all positional}).
594 @kwarg strict: See U{Python 3.14+ map<https://docs.Python.org/
595 3.14/library/functions.html#map>} (C{bool}).
597 @return: Function results (C{tuple}).
598 '''
599 return tuple(map(fun, *xs, **strict) if strict else map(fun, *xs))
602def max2(*xs):
603 '''Return 2-tuple C{(max(xs), xs.index(max(xs)))}.
604 '''
605 return _max2min2(xs, max, max2)
608def _max2min2(xs, _m, _m2):
609 '''(INTERNAL) Helper for C{max2} and C{min2}.
610 '''
611 if len(xs) == 1:
612 x = xs[0]
613 if isiterable(x) or isiterablen(x):
614 x, i = _m2(*x)
615 else:
616 i = 0
617 else:
618 x = _m(xs) # max or min
619 i = xs.index(x)
620 return x, i
623def min2(*xs):
624 '''Return 2-tuple C{(min(xs), xs.index(min(xs)))}.
625 '''
626 return _max2min2(xs, min, min2)
629def neg(x, neg0=None):
630 '''Negate C{x} and optionally, negate C{0.0} and C{-0.0}.
632 @kwarg neg0: Defines the return value for zero C{B{x}}: if C{None}
633 return C{0.0}, if C{True} return C{NEG0 if B{x}=0.0}
634 and C{0.0 if B{x}=NEG0} or if C{False} return C{B{x}}
635 I{as-is} (C{bool} or C{None}).
637 @return: C{-B{x} if B{x} else 0.0, NEG0 or B{x}}.
638 '''
639 return (-x) if x else (
640 _0_0 if neg0 is None else (
641 x if not neg0 else (
642 _0_0 if signBit(x) else _MODS.constants.
643 NEG0))) # PYCHOK indent
646def neg_(*xs):
647 '''Negate all C{xs} with L{neg}.
649 @return: A C{map(neg, B{xs})}.
650 '''
651 return map(neg, xs)
654def _neg0(x):
655 '''(INTERNAL) Return C{NEG0 if x < 0 else _0_0},
656 unlike C{_copysign_0_0} which returns C{_N_0_0}.
657 '''
658 return _MODS.constants.NEG0 if x < 0 else _0_0
661def _req_d_by(where, **name):
662 '''(INTERNAL) Get the fully qualified name.
663 '''
664 m = _MODS.named
665 n = m._name__(**name)
666 m = m.modulename(where, prefixed=True)
667 if n:
668 m = _DOT_(m, n)
669 return _SPACE_(_required_, _by_, m)
672def _reverange(n, stop=-1, step=-1):
673 '''(INTERNAL) Reversed range yielding C{n-1, n-1-step, ..., stop+1}.
674 '''
675 return range(n - 1, stop, step)
678def signBit(x):
679 '''Return C{signbit(B{x})}, like C++.
681 @return: C{True} if C{B{x} < 0} or C{NEG0} (C{bool}).
682 '''
683 return x < 0 or _MODS.constants.isneg0(x)
686def _signOf(x, ref): # in .fsums
687 '''(INTERNAL) Return the sign of B{C{x}} versus B{C{ref}}.
688 '''
689 return (-1) if x < ref else (+1 if x > ref else 0)
692def signOf(x):
693 '''Return sign of C{x} as C{int}.
695 @return: -1, 0 or +1 (C{int}).
696 '''
697 try:
698 s = x.signOf() # Fsum instance?
699 except AttributeError:
700 s = _signOf(x, 0)
701 return s
704def splice(iterable, n=2, **fill):
705 '''Split an iterable into C{n} slices.
707 @arg iterable: Items to be spliced (C{list}, C{tuple}, ...).
708 @kwarg n: Number of slices to generate (C{int}).
709 @kwarg fill: Optional fill value for missing items.
711 @return: A generator for each of B{C{n}} slices,
712 M{iterable[i::n] for i=0..n}.
714 @raise TypeError: Invalid B{C{n}}.
716 @note: Each generated slice is a C{tuple} or a C{list},
717 the latter only if the B{C{iterable}} is a C{list}.
719 @example:
721 >>> from pygeodesy import splice
723 >>> a, b = splice(range(10))
724 >>> a, b
725 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9))
727 >>> a, b, c = splice(range(10), n=3)
728 >>> a, b, c
729 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8))
731 >>> a, b, c = splice(range(10), n=3, fill=-1)
732 >>> a, b, c
733 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1))
735 >>> tuple(splice(list(range(9)), n=5))
736 ([0, 5], [1, 6], [2, 7], [3, 8], [4])
738 >>> splice(range(9), n=1)
739 <generator object splice at 0x0...>
740 '''
741 if not isint(n):
742 raise _TypeError(n=n)
744 t = _xiterablen(iterable)
745 if not isinstance(t, _list_tuple_types):
746 t = tuple(t)
748 if n > 1:
749 if fill:
750 fill = _xkwds_get1(fill, fill=MISSING)
751 if fill is not MISSING:
752 m = len(t) % n
753 if m > 0: # same type fill
754 t = t + type(t)((fill,) * (n - m))
755 for i in range(n):
756 # XXX t[i::n] chokes PyChecker
757 yield t[slice(i, None, n)]
758 else:
759 yield t # 1 slice, all
762def _splituple(strs, *sep_splits): # in .mgrs, ...
763 '''(INTERNAL) Split a C{comma}- or C{whitespace}-separated
764 string into a C{tuple} of stripped C{str}ings.
765 '''
766 t = (strs.split(*sep_splits) if sep_splits else
767 strs.replace(_COMMA_, _SPACE_).split()) if strs else ()
768 return tuple(s.strip() for s in t if s)
771def unsigned0(x):
772 '''Unsign if C{0.0}.
774 @return: C{B{x}} if B{C{x}} else C{0.0}.
775 '''
776 return x if x else _0_0
779def _xcopy(obj, deep=False):
780 '''(INTERNAL) Copy an object, shallow or deep.
782 @arg obj: The object to copy (any C{type}).
783 @kwarg deep: If C{True}, make a deep, otherwise
784 a shallow copy (C{bool}).
786 @return: The copy of B{C{obj}}.
787 '''
788 return _deepcopy(obj) if deep else _copy(obj)
791def _xcoverage(where, *required): # in .__main__ # PYCHOK no cover
792 '''(INTERNAL) Import C{coverage} and check required version.
793 '''
794 try:
795 _xpackages(_xcoverage)
796 import coverage
797 except ImportError as x:
798 raise _xImportError(x, where)
799 return _xversion(coverage, where, *required)
802def _xdup(obj, deep=False, **items):
803 '''(INTERNAL) Duplicate an object, replacing some attributes.
805 @arg obj: The object to copy (any C{type}).
806 @kwarg deep: If C{True}, copy deep, otherwise shallow (C{bool}).
807 @kwarg items: Attributes to be changed (C{any}).
809 @return: A duplicate of B{C{obj}} with modified
810 attributes, if any B{C{items}}.
812 @raise AttributeError: Some B{C{items}} invalid.
813 '''
814 d = _xcopy(obj, deep=deep)
815 for n, v in items.items():
816 if getattr(d, n, v) != v:
817 setattr(d, n, v)
818 elif not hasattr(d, n):
819 t = _MODS.named.classname(obj)
820 t = _SPACE_(_DOT_(t, n), _invalid_)
821 raise _AttributeError(txt=t, obj=obj, **items)
822# if items:
823# _MODS.props._update_all(d)
824 return d
827def _xgeographiclib(where, *required):
828 '''(INTERNAL) Import C{geographiclib} and check required version.
829 '''
830 try:
831 _xpackages(_xgeographiclib)
832 import geographiclib
833 except ImportError as x:
834 raise _xImportError(x, where, Error=LazyImportError)
835 return _xversion(geographiclib, where, *required)
838def _xImportError(exc, where, Error=_ImportError, **name):
839 '''(INTERNAL) Embellish an C{Lazy/ImportError}.
840 '''
841 t = _req_d_by(where, **name)
842 return Error(_Xstr(exc), txt=t, cause=exc)
845def _xinstanceof(*Types, **names_values):
846 '''(INTERNAL) Check C{Types} of all C{name=value} pairs.
848 @arg Types: One or more classes or types (C{class}), all
849 positional.
850 @kwarg names_values: One or more C{B{name}=value} pairs
851 with the C{value} to be checked.
853 @raise TypeError: One B{C{names_values}} pair is not an
854 instance of any of the B{C{Types}}.
855 '''
856 if not (Types and names_values):
857 raise _xAssertionError(_xinstanceof, *Types, **names_values)
859 for n, v in names_values.items():
860 if not isinstance(v, Types):
861 raise _TypesError(n, v, *Types)
864def _xiterable(obj):
865 '''(INTERNAL) Return C{obj} if iterable, otherwise raise C{TypeError}.
866 '''
867 return obj if isiterable(obj) else _xiterror(obj, _xiterable) # PYCHOK None
870def _xiterablen(obj):
871 '''(INTERNAL) Return C{obj} if iterable with C{__len__}, otherwise raise C{TypeError}.
872 '''
873 return obj if isiterablen(obj) else _xiterror(obj, _xiterablen) # PYCHOK None
876def _xiterror(obj, _xwhich):
877 '''(INTERNAL) Helper for C{_xinterable} and C{_xiterablen}.
878 '''
879 t = _not_(_xwhich.__name__[2:]) # _DUNDER_nameof
880 raise _TypeError(repr(obj), txt=t)
883def _xnumpy(where, *required):
884 '''(INTERNAL) Import C{numpy} and check required version.
885 '''
886 try:
887 _xpackages(_xnumpy)
888 import numpy
889 except ImportError as x:
890 raise _xImportError(x, where)
891 return _xversion(numpy, where, *required)
894def _xor(x, *xs):
895 '''(INTERNAL) Exclusive-or C{x} and C{xs}.
896 '''
897 for x_ in xs:
898 x ^= x_
899 return x
902def _xpackages(_xpkgf):
903 '''(INTERNAL) Check dependency to be excluded.
904 '''
905 if _XPACKAGES: # PYCHOK no cover
906 n = _xpkgf.__name__[2:] # _DUNDER_nameof, less '_x'
907 if n.lower() in _XPACKAGES:
908 E = _PYGEODESY(_xpackages)
909 x = _SPACE_(n, _in_, E)
910 e = _enquote(_getenv(E, NN))
911 raise ImportError(_EQUAL_(x, e))
914def _xscalar(**names_values):
915 '''(INTERNAL) Check all C{name=value} pairs to be C{scalar}.
916 '''
917 for n, v in names_values.items():
918 if not isscalar(v):
919 raise _TypeError(n, v, txt=_not_scalar_)
922def _xscipy(where, *required):
923 '''(INTERNAL) Import C{scipy} and check required version.
924 '''
925 try:
926 _xpackages(_xscipy)
927 import scipy
928 except ImportError as x:
929 raise _xImportError(x, where)
930 return _xversion(scipy, where, *required)
933def _xsubclassof(*Classes, **names_values):
934 '''(INTERNAL) Check (super) class of all C{name=value} pairs.
936 @arg Classes: One or more classes or types (C{class}), all
937 positional.
938 @kwarg names_values: One or more C{B{name}=value} pairs
939 with the C{value} to be checked.
941 @raise TypeError: One B{C{names_values}} pair is not a
942 (sub-)class of any of the B{C{Classes}}.
943 '''
944 if not (Classes and names_values):
945 raise _xAssertionError(_xsubclassof, *Classes, **names_values)
947 for n, v in names_values.items():
948 if not issubclassof(v, *Classes):
949 raise _TypesError(n, v, *Classes)
952def _xversion(package, where, *required, **name):
953 '''(INTERNAL) Check the C{package} version vs B{C{required}}.
954 '''
955 if required:
956 t = _version_info(package)
957 if t[:len(required)] < required:
958 t = _SPACE_(package.__name__, # _DUNDER_nameof
959 _version_, _DOT_(*t),
960 _below_, _DOT_(*required),
961 _req_d_by(where, **name))
962 raise ImportError(t)
963 return package
966def _xzip(*args, **strict): # PYCHOK no cover
967 '''(INTERNAL) Standard C{zip(..., strict=True)}.
968 '''
969 s = _xkwds_get1(strict, strict=True)
970 if s:
971 if _zip is zip: # < (3, 10)
972 t = _MODS.streprs.unstr(_xzip, *args, strict=s)
973 raise _NotImplementedError(t, txt=None)
974 return _zip(*args)
975 return zip(*args)
978if _MODS.sys_version_info2 < (3, 10): # see .errors
979 _zip = zip # PYCHOK exported
980else: # Python 3.10+
982 def _zip(*args):
983 return zip(*args, strict=True)
985_XPACKAGES = _splituple(_getenv(_PYGEODESY(_xpackages), NN).lower()) # test/bases._X_OK
987# **) MIT License
988#
989# Copyright (C) 2016-2025 -- mrJean1 at Gmail -- All Rights Reserved.
990#
991# Permission is hereby granted, free of charge, to any person obtaining a
992# copy of this software and associated documentation files (the "Software"),
993# to deal in the Software without restriction, including without limitation
994# the rights to use, copy, modify, merge, publish, distribute, sublicense,
995# and/or sell copies of the Software, and to permit persons to whom the
996# Software is furnished to do so, subject to the following conditions:
997#
998# The above copyright notice and this permission notice shall be included
999# in all copies or substantial portions of the Software.
1000#
1001# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
1002# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1003# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
1004# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
1005# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
1006# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
1007# OTHER DEALINGS IN THE SOFTWARE.