Coverage for pygeodesy/basics.py: 90%
276 statements
« prev ^ index » next coverage.py v7.6.1, created at 2025-05-04 12:01 -0400
« prev ^ index » next coverage.py v7.6.1, created at 2025-05-04 12:01 -0400
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, _envPYGEODESY, _getenv, _passarg, \
24 _PYGEODESY_ENV, typename, _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__ = '25.04.14'
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]
210try:
211 from math import gcd as _gcd
212except ImportError: # 3.4-
214 def _gcd(a, b): # PYCHOK redef
215 # <https://WikiPedia.org/wiki/Greatest_common_divisor>
216 a, b = int(a), int(b)
217 if b > a:
218 a, b = b, a
219# if b <= 0:
220# return 1
221 while b:
222 a, b = b, (a % b)
223 return a
226def halfs2(str2):
227 '''Split a string in 2 halfs.
229 @arg str2: String to split (C{str}).
231 @return: 2-Tuple C{(_1st, _2nd)} half (C{str}).
233 @raise ValueError: Zero or odd C{len(B{str2})}.
234 '''
235 h, r = divmod(len(str2), 2)
236 if r or not h:
237 raise _ValueError(str2=str2, txt=_odd_)
238 return str2[:h], str2[h:]
241def _integer_ratio2(x): # PYCHOK no cover
242 '''(INTERNAL) Return C{B{x}.as_interger_ratio()}.
243 '''
244 try: # int.as_integer_ratio in 3.8+
245 return x.as_integer_ratio()
246 except (AttributeError, OverflowError, TypeError, ValueError):
247 return (x if isint(x) else float(x)), 1
250def int1s(x): # PYCHOK no cover
251 '''Count the number of 1-bits in an C{int}, I{unsigned}.
253 @note: C{int1s(-B{x}) == int1s(abs(B{x}))}.
254 '''
255 try:
256 return x.bit_count() # Python 3.10+
257 except AttributeError:
258 # bin(-x) = '-' + bin(abs(x))
259 return bin(x).count(_1_)
262def isbool(obj):
263 '''Is B{C{obj}}ect a C{bool}ean?
265 @arg obj: The object (any C{type}).
267 @return: C{True} if C{bool}ean, C{False} otherwise.
268 '''
269 return isinstance(obj, bool) # and (obj is False
270# or obj is True)
272assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2
275def isCartesian(obj, ellipsoidal=None):
276 '''Is B{C{obj}}ect some C{Cartesian}?
278 @arg obj: The object (any C{type}).
279 @kwarg ellipsoidal: If C{None}, return the type of any C{Cartesian},
280 if C{True}, only an ellipsoidal C{Cartesian type}
281 or if C{False}, only a spherical C{Cartesian type}.
283 @return: C{type(B{obj}} if a C{Cartesian} of the required type, C{False}
284 if a C{Cartesian} of an other type or {None} otherwise.
285 '''
286 if ellipsoidal is not None:
287 try:
288 return obj.ellipsoidalCartesian if ellipsoidal else obj.sphericalCartesian
289 except AttributeError:
290 return None
291 return isinstanceof(obj, _MODS.cartesianBase.CartesianBase)
294def isclass(obj): # XXX avoid epydoc Python 2.7 error
295 '''Is B{C{obj}}ect a C{Class} or C{type}?
296 '''
297 return _MODS.inspect.isclass(obj)
300def iscomplex(obj, both=False):
301 '''Is B{C{obj}}ect a C{complex} or complex literal C{str}?
303 @arg obj: The object (any C{type}).
304 @kwarg both: If C{True}, check complex C{str} (C{bool}).
306 @return: C{True} if C{complex}, C{False} otherwise.
307 '''
308 try: # hasattr('conjugate', 'real' and 'imag')
309 return isinstance(obj, complex) or bool(both and isstr(obj) and
310 isinstance(complex(obj), complex)) # numbers.Complex?
311 except (TypeError, ValueError):
312 return False
315def isDEPRECATED(obj, outer=1):
316 '''Is B{C{obj}}ect or its outer C{type} a C{DEPRECATED}
317 class, constant, method or function?
319 @return: C{True} if C{DEPRECATED}, {False} if not or
320 C{None} if undetermined.
321 '''
322 r = None
323 for _ in range(max(0, outer) + 1):
324 try: # inspect.getdoc(obj)
325 if _DEPRECATED_ in obj.__doc__:
326 return True
327 r = False
328 except AttributeError:
329 pass
330 obj = type(obj)
331 return r
334def isfloat(obj, both=False):
335 '''Is B{C{obj}}ect a C{float} or float literal C{str}?
337 @arg obj: The object (any C{type}).
338 @kwarg both: If C{True}, check float C{str} (C{bool}).
340 @return: C{True} if C{float}, C{False} otherwise.
341 '''
342 try:
343 return isinstance(obj, float) or bool(both and
344 isstr(obj) and isinstance(float(obj), float))
345 except (TypeError, ValueError):
346 return False
349try:
350 isidentifier = str.isidentifier # Python 3, must be str
351except AttributeError: # Python 2-
353 def isidentifier(obj):
354 '''Is B{C{obj}}ect a Python identifier?
355 '''
356 return bool(obj and isstr(obj)
357 and obj.replace(_UNDER_, NN).isalnum()
358 and not obj[:1].isdigit())
361def _isin(obj, *objs):
362 '''(INTERNAL) Return C{bool(obj in objs)} with C{True} and C{False} matching.
363 '''
364 return any(o is obj for o in objs) or \
365 any(o == obj for o in objs if not isbool(o))
368def isinstanceof(obj, *Classes):
369 '''Is B{C{obj}}ect an instance of one of the C{Classes}?
371 @arg obj: The object (any C{type}).
372 @arg Classes: One or more classes (C{Class}).
374 @return: C{type(B{obj}} if one of the B{C{Classes}},
375 C{None} otherwise.
376 '''
377 return type(obj) if isinstance(obj, Classes) else None
380def isint(obj, both=False):
381 '''Is B{C{obj}}ect an C{int} or integer C{float} value?
383 @arg obj: The object (any C{type}).
384 @kwarg both: If C{True}, check C{float} and L{Fsum}
385 type and value (C{bool}).
387 @return: C{True} if C{int} or I{integer} C{float}
388 or L{Fsum}, C{False} otherwise.
390 @note: Both C{isint(True)} and C{isint(False)} return
391 C{False} (and no longer C{True}).
392 '''
393 if isinstance(obj, _Ints):
394 return not isbool(obj)
395 elif both: # and isinstance(obj, (float, Fsum))
396 try: # NOT , _Scalars) to include Fsum!
397 return obj.is_integer()
398 except AttributeError:
399 pass # XXX float(int(obj)) == obj?
400 return False
403def isiterable(obj, strict=False):
404 '''Is B{C{obj}}ect C{iterable}?
406 @arg obj: The object (any C{type}).
407 @kwarg strict: If C{True}, check class attributes (C{bool}).
409 @return: C{True} if C{iterable}, C{False} otherwise.
410 '''
411 # <https://PyPI.org/project/isiterable/>
412 return bool(isiterabletype(obj)) if strict else hasattr(obj, '__iter__') # map, range, set
415def isiterablen(obj, strict=False):
416 '''Is B{C{obj}}ect C{iterable} and has C{len}gth?
418 @arg obj: The object (any C{type}).
419 @kwarg strict: If C{True}, check class attributes (C{bool}).
421 @return: C{True} if C{iterable} with C{len}gth, C{False} otherwise.
422 '''
423 _has = isiterabletype if strict else hasattr
424 return bool(_has(obj, '__len__') and _has(obj, '__getitem__'))
427def isiterabletype(obj, method='__iter__'):
428 '''Is B{C{obj}}ect an instance of an C{iterable} class or type?
430 @arg obj: The object (any C{type}).
431 @kwarg method: The name of the required method (C{str}).
433 @return: The C{base-class} if C{iterable}, C{None} otherwise.
434 '''
435 try: # <https://StackOverflow.com/questions/73568964>
436 for b in type(obj).__mro__[:-1]: # ignore C{object}
437 try:
438 if callable(b.__dict__[method]):
439 return b
440 except (AttributeError, KeyError):
441 pass
442 except (AttributeError, TypeError):
443 pass
444 return None
447try:
448 from keyword import iskeyword # Python 2.7+
449except ImportError:
451 def iskeyword(unused):
452 '''Not Implemented, C{False} always.
453 '''
454 return False
457def isLatLon(obj, ellipsoidal=None):
458 '''Is B{C{obj}}ect some C{LatLon}?
460 @arg obj: The object (any C{type}).
461 @kwarg ellipsoidal: If C{None}, return the type of any C{LatLon},
462 if C{True}, only an ellipsoidal C{LatLon type}
463 or if C{False}, only a spherical C{LatLon type}.
465 @return: C{type(B{obj}} if a C{LatLon} of the required type, C{False}
466 if a C{LatLon} of an other type or {None} otherwise.
467 '''
468 if ellipsoidal is not None:
469 try:
470 return obj.ellipsoidalLatLon if ellipsoidal else obj.sphericalLatLon
471 except AttributeError:
472 return None
473 return isinstanceof(obj, _MODS.latlonBase.LatLonBase)
476def islistuple(obj, minum=0):
477 '''Is B{C{obj}}ect a C{list} or C{tuple} with non-zero length?
479 @arg obj: The object (any C{type}).
480 @kwarg minum: Minimal C{len} required C({int}).
482 @return: C{True} if a C{list} or C{tuple} with C{len} at
483 least B{C{minum}}, C{False} otherwise.
484 '''
485 return isinstance(obj, _list_tuple_types) and len(obj) >= minum
488def isNvector(obj, ellipsoidal=None):
489 '''Is B{C{obj}}ect some C{Nvector}?
491 @arg obj: The object (any C{type}).
492 @kwarg ellipsoidal: If C{None}, return the type of any C{Nvector},
493 if C{True}, only an ellipsoidal C{Nvector type}
494 or if C{False}, only a spherical C{Nvector type}.
496 @return: C{type(B{obj}} if an C{Nvector} of the required type, C{False}
497 if an C{Nvector} of an other type or {None} otherwise.
498 '''
499 if ellipsoidal is not None:
500 try:
501 return obj.ellipsoidalNvector if ellipsoidal else obj.sphericalNvector
502 except AttributeError:
503 return None
504 return isinstanceof(obj, _MODS.nvectorBase.NvectorBase)
507def isodd(x):
508 '''Is B{C{x}} odd?
510 @arg x: Value (C{scalar}).
512 @return: C{True} if odd, C{False} otherwise.
513 '''
514 return bool(int(x) & 1) # == bool(int(x) % 2)
517def isscalar(obj, both=False):
518 '''Is B{C{obj}}ect an C{int} or integer C{float} value?
520 @arg obj: The object (any C{type}).
521 @kwarg both: If C{True}, check L{Fsum} and L{Fsum2Tuple}
522 residuals.
524 @return: C{True} if C{int}, C{float} or C{Fsum/-2Tuple}
525 with zero residual, C{False} otherwise.
526 '''
527 if isinstance(obj, _Scalars):
528 return not isbool(obj) # exclude bool
529 elif both and _MODS.fsums._isFsum_2Tuple(obj):
530 return bool(obj.residual == 0)
531 return False
534def issequence(obj, *excls):
535 '''Is B{C{obj}}ect some sequence type?
537 @arg obj: The object (any C{type}).
538 @arg excls: Classes to exclude (C{type}), all positional.
540 @note: Excluding C{tuple} implies excluding C{namedtuple}.
542 @return: C{True} if a sequence, C{False} otherwise.
543 '''
544 return isinstance(obj, _Seqs) and not (excls and isinstance(obj, excls))
547def isstr(obj):
548 '''Is B{C{obj}}ect some string type?
550 @arg obj: The object (any C{type}).
552 @return: C{True} if a C{str}, C{bytes}, ...,
553 C{False} otherwise.
554 '''
555 return isinstance(obj, _Strs)
558def issubclassof(Sub, *Supers):
559 '''Is B{C{Sub}} a class and sub-class of some other class(es)?
561 @arg Sub: The sub-class (C{Class}).
562 @arg Supers: One or more C(super) classes (C{Class}).
564 @return: C{True} if a sub-class of any B{C{Supers}}, C{False}
565 if not (C{bool}) or C{None} if not a class or if no
566 B{C{Supers}} are given or none of those are a class.
567 '''
568 if isclass(Sub):
569 t = tuple(S for S in Supers if isclass(S))
570 if t:
571 return bool(issubclass(Sub, t)) # built-in
572 return None
575def itemsorted(adict, *items_args, **asorted_reverse):
576 '''Return the items of C{B{adict}} sorted I{alphabetically,
577 case-insensitively} and in I{ascending} order.
579 @arg items_args: Optional positional argument(s) for method
580 C{B{adict}.items(B*{items_args})}.
581 @kwarg asorted_reverse: Use C{B{asorted}=False} for I{alphabetical,
582 case-sensitive} sorting and C{B{reverse}=True} for
583 sorting in C{descending} order.
584 '''
585 def _ins(item): # functools.cmp_to_key
586 k, v = item
587 return k.lower()
589 def _reverse_key(asorted=True, reverse=False):
590 return dict(reverse=reverse, key=_ins if asorted else None)
592 items = adict.items(*items_args) if items_args else adict.items()
593 return sorted(items, **_reverse_key(**asorted_reverse))
596def len2(items):
597 '''Make built-in function L{len} work for generators, iterators,
598 etc. since those can only be started exactly once.
600 @arg items: Generator, iterator, list, range, tuple, etc.
602 @return: 2-Tuple C{(n, items)} of the number of items (C{int})
603 and the items (C{list} or C{tuple}).
604 '''
605 if not isinstance(items, _Seqs): # NOT hasattr(items, '__len__'):
606 items = list(items)
607 return len(items), items
610def map1(fun1, *xs): # XXX map_
611 '''Call a single-argument function to each B{C{xs}}
612 and return a C{tuple} of results.
614 @arg fun1: 1-Arg function (C{callable}).
615 @arg xs: Arguments (C{any positional}).
617 @return: Function results (C{tuple}).
618 '''
619 return tuple(map(fun1, xs)) # if len(xs) != 1 else fun1(xs[0])
622def map2(fun, *xs, **strict):
623 '''Like Python's B{C{map}} but returning a C{tuple} of results.
625 Unlike Python 2's built-in L{map}, Python 3+ L{map} returns a
626 L{map} object, an iterator-like object which generates the
627 results only once. Converting the L{map} object to a tuple
628 maintains the Python 2 behavior.
630 @arg fun: Function (C{callable}).
631 @arg xs: Arguments (C{all positional}).
632 @kwarg strict: See U{Python 3.14+ map<https://docs.Python.org/
633 3.14/library/functions.html#map>} (C{bool}).
635 @return: Function results (C{tuple}).
636 '''
637 return tuple(map(fun, *xs, **strict) if strict else map(fun, *xs))
640def max2(*xs):
641 '''Return 2-tuple C{(max(xs), xs.index(max(xs)))}.
642 '''
643 return _max2min2(xs, max, max2)
646def _max2min2(xs, _m, _m2):
647 '''(INTERNAL) Helper for C{max2} and C{min2}.
648 '''
649 if len(xs) == 1:
650 x = xs[0]
651 if isiterable(x) or isiterablen(x):
652 x, i = _m2(*x)
653 else:
654 i = 0
655 else:
656 x = _m(xs) # max or min
657 i = xs.index(x)
658 return x, i
661def min2(*xs):
662 '''Return 2-tuple C{(min(xs), xs.index(min(xs)))}.
663 '''
664 return _max2min2(xs, min, min2)
667def neg(x, neg0=None):
668 '''Negate C{x} and optionally, negate C{0.0} and C{-0.0}.
670 @kwarg neg0: Defines the return value for zero C{B{x}}: if C{None}
671 return C{0.0}, if C{True} return C{NEG0 if B{x}=0.0}
672 and C{0.0 if B{x}=NEG0} or if C{False} return C{B{x}}
673 I{as-is} (C{bool} or C{None}).
675 @return: C{-B{x} if B{x} else 0.0, NEG0 or B{x}}.
676 '''
677 return (-x) if x else (
678 _0_0 if neg0 is None else (
679 x if not neg0 else (
680 _0_0 if signBit(x) else _MODS.constants.
681 NEG0))) # PYCHOK indent
684def neg_(*xs):
685 '''Negate all C{xs} with L{neg}.
687 @return: A C{map(neg, B{xs})}.
688 '''
689 return map(neg, xs)
692def _neg0(x):
693 '''(INTERNAL) Return C{NEG0 if x < 0 else _0_0},
694 unlike C{_copysign_0_0} which returns C{_N_0_0}.
695 '''
696 return _MODS.constants.NEG0 if x < 0 else _0_0
699def _req_d_by(where, **name):
700 '''(INTERNAL) Get the fully qualified name.
701 '''
702 m = _MODS.named
703 n = m._name__(**name)
704 m = m.modulename(where, prefixed=True)
705 if n:
706 m = _DOT_(m, n)
707 return _SPACE_(_required_, _by_, m)
710def _reverange(n, stop=-1, step=-1):
711 '''(INTERNAL) Reversed range yielding C{n-1, n-1-step, ..., stop+1}.
712 '''
713 return range(n - 1, stop, step)
716def signBit(x):
717 '''Return C{signbit(B{x})}, like C++.
719 @return: C{True} if C{B{x} < 0} or C{NEG0} (C{bool}).
720 '''
721 return x < 0 or _MODS.constants.isneg0(x)
724def _signOf(x, ref): # in .fsums
725 '''(INTERNAL) Return the sign of B{C{x}} versus B{C{ref}}.
726 '''
727 return (-1) if x < ref else (+1 if x > ref else 0)
730def signOf(x):
731 '''Return sign of C{x} as C{int}.
733 @return: -1, 0 or +1 (C{int}).
734 '''
735 try:
736 s = x.signOf() # Fsum instance?
737 except AttributeError:
738 s = _signOf(x, 0)
739 return s
742def splice(iterable, n=2, **fill):
743 '''Split an iterable into C{n} slices.
745 @arg iterable: Items to be spliced (C{list}, C{tuple}, ...).
746 @kwarg n: Number of slices to generate (C{int}).
747 @kwarg fill: Optional fill value for missing items.
749 @return: A generator for each of B{C{n}} slices,
750 M{iterable[i::n] for i=0..n}.
752 @raise TypeError: Invalid B{C{n}}.
754 @note: Each generated slice is a C{tuple} or a C{list},
755 the latter only if the B{C{iterable}} is a C{list}.
757 @example:
759 >>> from pygeodesy import splice
761 >>> a, b = splice(range(10))
762 >>> a, b
763 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9))
765 >>> a, b, c = splice(range(10), n=3)
766 >>> a, b, c
767 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8))
769 >>> a, b, c = splice(range(10), n=3, fill=-1)
770 >>> a, b, c
771 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1))
773 >>> tuple(splice(list(range(9)), n=5))
774 ([0, 5], [1, 6], [2, 7], [3, 8], [4])
776 >>> splice(range(9), n=1)
777 <generator object splice at 0x0...>
778 '''
779 if not isint(n):
780 raise _TypeError(n=n)
782 t = _xiterablen(iterable)
783 if not isinstance(t, _list_tuple_types):
784 t = tuple(t)
786 if n > 1:
787 if fill:
788 fill = _xkwds_get1(fill, fill=MISSING)
789 if fill is not MISSING:
790 m = len(t) % n
791 if m > 0: # same type fill
792 t = t + type(t)((fill,) * (n - m))
793 for i in range(n):
794 # XXX t[i::n] chokes PyChecker
795 yield t[slice(i, None, n)]
796 else:
797 yield t # 1 slice, all
800def _splituple(strs, *sep_splits): # in .mgrs, ...
801 '''(INTERNAL) Split a C{comma}- or C{whitespace}-separated
802 string into a C{tuple} of stripped C{str}ings.
803 '''
804 if sep_splits:
805 t = (t.strip() for t in strs.split(*sep_splits))
806 else:
807 t = strs.strip()
808 if t:
809 t = t.replace(_COMMA_, _SPACE_).split()
810 return tuple(t) if t else ()
813def unsigned0(x):
814 '''Unsign if C{0.0}.
816 @return: C{B{x}} if B{C{x}} else C{0.0}.
817 '''
818 return x if x else _0_0
821def _xcopy(obj, deep=False):
822 '''(INTERNAL) Copy an object, shallow or deep.
824 @arg obj: The object to copy (any C{type}).
825 @kwarg deep: If C{True}, make a deep, otherwise
826 a shallow copy (C{bool}).
828 @return: The copy of B{C{obj}}.
829 '''
830 return _deepcopy(obj) if deep else _copy(obj)
833def _xcoverage(where, *required): # in .__main__ # PYCHOK no cover
834 '''(INTERNAL) Import C{coverage} and check required version.
835 '''
836 try:
837 _xpackages(_xcoverage)
838 import coverage
839 except ImportError as x:
840 raise _xImportError(x, where)
841 return _xversion(coverage, where, *required)
844def _xdup(obj, deep=False, **items):
845 '''(INTERNAL) Duplicate an object, replacing some attributes.
847 @arg obj: The object to copy (any C{type}).
848 @kwarg deep: If C{True}, copy deep, otherwise shallow (C{bool}).
849 @kwarg items: Attributes to be changed (C{any}).
851 @return: A duplicate of B{C{obj}} with modified
852 attributes, if any B{C{items}}.
854 @raise AttributeError: Some B{C{items}} invalid.
855 '''
856 d = _xcopy(obj, deep=deep)
857 for n, v in items.items():
858 if getattr(d, n, v) != v:
859 setattr(d, n, v)
860 elif not hasattr(d, n):
861 t = _MODS.named.classname(obj)
862 t = _SPACE_(_DOT_(t, n), _invalid_)
863 raise _AttributeError(txt=t, obj=obj, **items)
864# if items:
865# _MODS.props._update_all(d)
866 return d
869def _xgeographiclib(where, *required):
870 '''(INTERNAL) Import C{geographiclib} and check required version.
871 '''
872 try:
873 _xpackages(_xgeographiclib)
874 import geographiclib
875 except ImportError as x:
876 raise _xImportError(x, where, Error=LazyImportError)
877 return _xversion(geographiclib, where, *required)
880def _xImportError(exc, where, Error=_ImportError, **name):
881 '''(INTERNAL) Embellish an C{Lazy/ImportError}.
882 '''
883 t = _req_d_by(where, **name)
884 return Error(_Xstr(exc), txt=t, cause=exc)
887def _xinstanceof(*Types, **names_values):
888 '''(INTERNAL) Check C{Types} of all C{name=value} pairs.
890 @arg Types: One or more classes or types (C{class}), all
891 positional.
892 @kwarg names_values: One or more C{B{name}=value} pairs
893 with the C{value} to be checked.
895 @raise TypeError: One B{C{names_values}} pair is not an
896 instance of any of the B{C{Types}}.
897 '''
898 if not (Types and names_values):
899 raise _xAssertionError(_xinstanceof, *Types, **names_values)
901 for n, v in names_values.items():
902 if not isinstance(v, Types):
903 raise _TypesError(n, v, *Types)
906def _xiterable(obj):
907 '''(INTERNAL) Return C{obj} if iterable, otherwise raise C{TypeError}.
908 '''
909 return obj if isiterable(obj) else _xiterror(obj, _xiterable) # PYCHOK None
912def _xiterablen(obj):
913 '''(INTERNAL) Return C{obj} if iterable with C{__len__}, otherwise raise C{TypeError}.
914 '''
915 return obj if isiterablen(obj) else _xiterror(obj, _xiterablen) # PYCHOK None
918def _xiterror(obj, _xwhich):
919 '''(INTERNAL) Helper for C{_xinterable} and C{_xiterablen}.
920 '''
921 t = typename(_xwhich)[2:] # less '_x'
922 raise _TypeError(repr(obj), txt=_not_(t))
925def _xnumpy(where, *required):
926 '''(INTERNAL) Import C{numpy} and check required version.
927 '''
928 try:
929 _xpackages(_xnumpy)
930 import numpy
931 except ImportError as x:
932 raise _xImportError(x, where)
933 return _xversion(numpy, where, *required)
936def _xor(x, *xs):
937 '''(INTERNAL) Exclusive-or C{x} and C{xs}.
938 '''
939 for x_ in xs:
940 x ^= x_
941 return x
944def _xpackages(_xhich):
945 '''(INTERNAL) Check dependency to be excluded.
946 '''
947 if _XPACKAGES: # PYCHOK no cover
948 n = typename(_xhich)[2:] # less '_x'
949 if n.lower() in _XPACKAGES:
950 E = _PYGEODESY_ENV(_xpackages_)
951 x = _SPACE_(n, _in_, E)
952 e = _enquote(_getenv(E, NN))
953 raise ImportError(_EQUAL_(x, e))
956def _xscalar(**names_values):
957 '''(INTERNAL) Check all C{name=value} pairs to be C{scalar}.
958 '''
959 for n, v in names_values.items():
960 if not isscalar(v):
961 raise _TypeError(n, v, txt=_not_scalar_)
964def _xscipy(where, *required):
965 '''(INTERNAL) Import C{scipy} and check required version.
966 '''
967 try:
968 _xpackages(_xscipy)
969 import scipy
970 except ImportError as x:
971 raise _xImportError(x, where)
972 return _xversion(scipy, where, *required)
975def _xsubclassof(*Classes, **names_values):
976 '''(INTERNAL) Check (super) class of all C{name=value} pairs.
978 @arg Classes: One or more classes or types (C{class}), all
979 positional.
980 @kwarg names_values: One or more C{B{name}=value} pairs
981 with the C{value} to be checked.
983 @raise TypeError: One B{C{names_values}} pair is not a
984 (sub-)class of any of the B{C{Classes}}.
985 '''
986 if not (Classes and names_values):
987 raise _xAssertionError(_xsubclassof, *Classes, **names_values)
989 for n, v in names_values.items():
990 if not issubclassof(v, *Classes):
991 raise _TypesError(n, v, *Classes)
994def _xversion(package, where, *required, **name):
995 '''(INTERNAL) Check the C{package} version vs B{C{required}}.
996 '''
997 if required:
998 t = _version_info(package)
999 if t[:len(required)] < required:
1000 t = _SPACE_(typename(package),
1001 _version_, _DOT_(*t),
1002 _below_, _DOT_(*required),
1003 _req_d_by(where, **name))
1004 raise ImportError(t)
1005 return package
1008def _xzip(*args, **strict): # PYCHOK no cover
1009 '''(INTERNAL) Standard C{zip(..., strict=True)}.
1010 '''
1011 s = _xkwds_get1(strict, strict=True)
1012 if s:
1013 if _zip is zip: # < (3, 10)
1014 t = _MODS.streprs.unstr(_xzip, *args, strict=s)
1015 raise _NotImplementedError(t, txt=None)
1016 return _zip(*args)
1017 return zip(*args)
1020if _MODS.sys_version_info2 < (3, 10): # see .errors
1021 _zip = zip # PYCHOK exported
1022else: # Python 3.10+
1024 def _zip(*args):
1025 return zip(*args, strict=True)
1027_xpackages_ = typename(_xpackages).lstrip(_UNDER_)
1028_XPACKAGES = _splituple(_envPYGEODESY(_xpackages_).lower()) # test/bases._X_OK
1030# **) MIT License
1031#
1032# Copyright (C) 2016-2025 -- mrJean1 at Gmail -- All Rights Reserved.
1033#
1034# Permission is hereby granted, free of charge, to any person obtaining a
1035# copy of this software and associated documentation files (the "Software"),
1036# to deal in the Software without restriction, including without limitation
1037# the rights to use, copy, modify, merge, publish, distribute, sublicense,
1038# and/or sell copies of the Software, and to permit persons to whom the
1039# Software is furnished to do so, subject to the following conditions:
1040#
1041# The above copyright notice and this permission notice shall be included
1042# in all copies or substantial portions of the Software.
1043#
1044# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
1045# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1046# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
1047# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
1048# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
1049# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
1050# OTHER DEALINGS IN THE SOFTWARE.