Coverage for pygeodesy/basics.py: 95%

244 statements  

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1 

2# -*- coding: utf-8 -*- 

3 

4u'''Some, basic definitions, functions and dependencies. 

5 

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 

16 

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_get 

22from pygeodesy.internals import _0_0, _enquote, _passarg, _version_info 

23from pygeodesy.interns import MISSING, NN, _1_, _by_, _COMMA_, _DOT_, _DEPRECATED_, \ 

24 _ELLIPSIS4_, _EQUAL_, _in_, _invalid_, _N_A_, _not_, \ 

25 _not_scalar_, _odd_, _SPACE_, _UNDER_, _version_ 

26# from pygeodesy.latlonBase import LatLonBase # _MODS 

27from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS, _FOR_DOCS, _getenv, \ 

28 LazyImportError, _sys_version_info2 

29# from pygeodesy.named import classname, modulename, _name__ # _MODS 

30# from pygeodesy.nvectorBase import NvectorBase # _MODS 

31# from pygeodesy.props import _update_all # _MODS 

32# from pygeodesy.streprs import Fmt # _MODS 

33 

34from copy import copy as _copy, deepcopy as _deepcopy 

35from math import copysign as _copysign 

36import inspect as _inspect 

37 

38__all__ = _ALL_LAZY.basics 

39__version__ = '24.05.21' 

40 

41_below_ = 'below' 

42_list_tuple_types = (list, tuple) 

43_PYGEODESY_XPACKAGES_ = 'PYGEODESY_XPACKAGES' 

44_required_ = 'required' 

45 

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 

54 

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 

68 

69try: 

70 _Bytes = unicode, bytearray # PYCHOK expected 

71 _Strs = basestring, str # XXX , bytes 

72 str2ub = ub2str = _passarg # avoids UnicodeDecodeError 

73 

74 def _Xstr(exc): # PYCHOK no cover 

75 '''I{Invoke only with caught ImportError} B{C{exc}}. 

76 

77 C{... "can't import name _distributor_init" ...} 

78 

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 

91 

92except NameError: # Python 3+ 

93 from pygeodesy.interns import _utf_8_ 

94 

95 _Bytes = bytes, bytearray 

96 _Strs = str, # tuple 

97 _Xstr = str 

98 

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 

105 

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 

112 

113 

114def _args_kwds_names(func): 

115 '''(INTERNAL) Get a C{func}'s args and kwds names, including 

116 C{self} for methods. 

117 

118 @note: Python 2 may I{not} include the C{*args} nor the 

119 C{**kwds} names. 

120 ''' 

121 try: 

122 args_kwds = _inspect.signature(func).parameters.keys() 

123 except AttributeError: # .signature new Python 3+ 

124 args_kwds = _inspect.getargspec(func).args 

125 return tuple(args_kwds) 

126 

127 

128def clips(sb, limit=50, white=NN): 

129 '''Clip a string to the given length limit. 

130 

131 @arg sb: String (C{str} or C{bytes}). 

132 @kwarg limit: Length limit (C{int}). 

133 @kwarg white: Optionally, replace all whitespace (C{str}). 

134 

135 @return: The clipped or unclipped B{C{sb}}. 

136 ''' 

137 T = type(sb) 

138 if len(sb) > limit > 8: 

139 h = limit // 2 

140 sb = T(_ELLIPSIS4_).join((sb[:h], sb[-h:])) 

141 if white: # replace whitespace 

142 sb = T(white).join(sb.split()) 

143 return sb 

144 

145 

146def copysign0(x, y): 

147 '''Like C{math.copysign(x, y)} except C{zero}, I{unsigned}. 

148 

149 @return: C{math.copysign(B{x}, B{y})} if B{C{x}} else 

150 C{type(B{x})(0)}. 

151 ''' 

152 return _copysign(x, (y if y else 0)) if x else copytype(0, x) 

153 

154 

155def copytype(x, y): 

156 '''Return the value of B{x} as C{type} of C{y}. 

157 

158 @return: C{type(B{y})(B{x})}. 

159 ''' 

160 return type(y)(x if x else _0_0) 

161 

162 

163def halfs2(str2): 

164 '''Split a string in 2 halfs. 

165 

166 @arg str2: String to split (C{str}). 

167 

168 @return: 2-Tuple C{(_1st, _2nd)} half (C{str}). 

169 

170 @raise ValueError: Zero or odd C{len(B{str2})}. 

171 ''' 

172 h, r = divmod(len(str2), 2) 

173 if r or not h: 

174 raise _ValueError(str2=str2, txt=_odd_) 

175 return str2[:h], str2[h:] 

176 

177 

178def int1s(x): 

179 '''Count the number of 1-bits in an C{int}, I{unsigned}. 

180 

181 @note: C{int1s(-B{x}) == int1s(abs(B{x}))}. 

182 ''' 

183 try: 

184 return x.bit_count() # Python 3.10+ 

185 except AttributeError: 

186 # bin(-x) = '-' + bin(abs(x)) 

187 return bin(x).count(_1_) 

188 

189 

190def isbool(obj): 

191 '''Is B{C{obj}}ect a C{bool}ean? 

192 

193 @arg obj: The object (any C{type}). 

194 

195 @return: C{True} if C{bool}ean, C{False} otherwise. 

196 ''' 

197 return isinstance(obj, bool) # and (obj is False 

198# or obj is True) 

199 

200assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2 

201 

202 

203def isCartesian(obj, ellipsoidal=None): 

204 '''Is B{C{obj}}ect some C{Cartesian}? 

205 

206 @arg obj: The object (any C{type}). 

207 @kwarg ellipsoidal: If C{None}, return the type of any C{Cartesian}, 

208 if C{True}, only an ellipsoidal C{Cartesian type} 

209 or if C{False}, only a spherical C{Cartesian type}. 

210 

211 @return: C{type(B{obj}} if a C{Cartesian} of the required type, C{False} 

212 if a C{Cartesian} of an other type or {None} otherwise. 

213 ''' 

214 if ellipsoidal is not None: 

215 try: 

216 return obj.ellipsoidalCartesian if ellipsoidal else obj.sphericalCartesian 

217 except AttributeError: 

218 return None 

219 return isinstanceof(obj, _MODS.cartesianBase.CartesianBase) 

220 

221 

222if _FOR_DOCS: # XXX avoid epydoc Python 2.7 error 

223 

224 def isclass(obj): 

225 '''Is B{C{obj}}ect a C{Class} or C{type}? 

226 ''' 

227 return _inspect.isclass(obj) 

228else: 

229 isclass = _inspect.isclass 

230 

231 

232def iscomplex(obj, both=False): 

233 '''Is B{C{obj}}ect a C{complex} or complex literal C{str}? 

234 

235 @arg obj: The object (any C{type}). 

236 @kwarg both: If C{True}, check complex C{str} (C{bool}). 

237 

238 @return: C{True} if C{complex}, C{False} otherwise. 

239 ''' 

240 try: # hasattr('conjugate', 'real' and 'imag') 

241 return isinstance(obj, complex) or bool(both and isstr(obj) and 

242 isinstance(complex(obj), complex)) # numbers.Complex? 

243 except (TypeError, ValueError): 

244 return False 

245 

246 

247def isDEPRECATED(obj): 

248 '''Is B{C{obj}}ect a C{DEPRECATED} class, method or function? 

249 

250 @return: C{True} if C{DEPRECATED}, {False} if not or 

251 C{None} if undetermined. 

252 ''' 

253 try: # XXX inspect.getdoc(obj) or obj.__doc__ 

254 doc = obj.__doc__.lstrip() 

255 return bool(doc and doc.startswith(_DEPRECATED_)) 

256 except AttributeError: 

257 return None 

258 

259 

260def isfloat(obj, both=False): 

261 '''Is B{C{obj}}ect a C{float} or float literal C{str}? 

262 

263 @arg obj: The object (any C{type}). 

264 @kwarg both: If C{True}, check float C{str} (C{bool}). 

265 

266 @return: C{True} if C{float}, C{False} otherwise. 

267 ''' 

268 try: 

269 return isinstance(obj, float) or bool(both and 

270 isstr(obj) and isinstance(float(obj), float)) 

271 except (TypeError, ValueError): 

272 return False 

273 

274 

275try: 

276 isidentifier = str.isidentifier # Python 3, must be str 

277except AttributeError: # Python 2- 

278 

279 def isidentifier(obj): 

280 '''Is B{C{obj}}ect a Python identifier? 

281 ''' 

282 return bool(obj and isstr(obj) 

283 and obj.replace(_UNDER_, NN).isalnum() 

284 and not obj[:1].isdigit()) 

285 

286 

287def isinstanceof(obj, *Classes): 

288 '''Is B{C{obj}}ect an instance of one of the C{Classes}? 

289 

290 @arg obj: The object (any C{type}). 

291 @arg Classes: One or more classes (C{Class}). 

292 

293 @return: C{type(B{obj}} if one of the B{C{Classes}}, 

294 C{None} otherwise. 

295 ''' 

296 return type(obj) if isinstance(obj, Classes) else None 

297 

298 

299def isint(obj, both=False): 

300 '''Is B{C{obj}}ect an C{int} or integer C{float} value? 

301 

302 @arg obj: The object (any C{type}). 

303 @kwarg both: If C{True}, check C{float} and L{Fsum} 

304 type and value (C{bool}). 

305 

306 @return: C{True} if C{int} or I{integer} C{float} 

307 or L{Fsum}, C{False} otherwise. 

308 

309 @note: Both C{isint(True)} and C{isint(False)} return 

310 C{False} (and no longer C{True}). 

311 ''' 

312 if isinstance(obj, _Ints): 

313 return not isbool(obj) 

314 elif both: # and isinstance(obj, (float, Fsum)) 

315 try: # NOT , _Scalars) to include Fsum! 

316 return obj.is_integer() 

317 except AttributeError: 

318 pass # XXX float(int(obj)) == obj? 

319 return False 

320 

321 

322def isiterable(obj): 

323 '''Is B{C{obj}}ect C{iterable}? 

324 

325 @arg obj: The object (any C{type}). 

326 

327 @return: C{True} if C{iterable}, C{False} otherwise. 

328 ''' 

329 # <https://PyPI.org/project/isiterable/> 

330 return hasattr(obj, '__iter__') # map, range, set 

331 

332 

333def isiterablen(obj): 

334 '''Is B{C{obj}}ect C{iterable} and has C{len}gth? 

335 

336 @arg obj: The object (any C{type}). 

337 

338 @return: C{True} if C{iterable} with C{len}gth, C{False} otherwise. 

339 ''' 

340 return hasattr(obj, '__len__') and hasattr(obj, '__getitem__') 

341 

342 

343try: 

344 from keyword import iskeyword # Python 2.7+ 

345except ImportError: 

346 

347 def iskeyword(unused): 

348 '''Not Implemented, C{False} always. 

349 ''' 

350 return False 

351 

352 

353def isLatLon(obj, ellipsoidal=None): 

354 '''Is B{C{obj}}ect some C{LatLon}? 

355 

356 @arg obj: The object (any C{type}). 

357 @kwarg ellipsoidal: If C{None}, return the type of any C{LatLon}, 

358 if C{True}, only an ellipsoidal C{LatLon type} 

359 or if C{False}, only a spherical C{LatLon type}. 

360 

361 @return: C{type(B{obj}} if a C{LatLon} of the required type, C{False} 

362 if a C{LatLon} of an other type or {None} otherwise. 

363 ''' 

364 if ellipsoidal is not None: 

365 try: 

366 return obj.ellipsoidalLatLon if ellipsoidal else obj.sphericalLatLon 

367 except AttributeError: 

368 return None 

369 return isinstanceof(obj, _MODS.latlonBase.LatLonBase) 

370 

371 

372def islistuple(obj, minum=0): 

373 '''Is B{C{obj}}ect a C{list} or C{tuple} with non-zero length? 

374 

375 @arg obj: The object (any C{type}). 

376 @kwarg minum: Minimal C{len} required C({int}). 

377 

378 @return: C{True} if a C{list} or C{tuple} with C{len} at 

379 least B{C{minum}}, C{False} otherwise. 

380 ''' 

381 return isinstance(obj, _list_tuple_types) and len(obj) >= minum 

382 

383 

384def isNvector(obj, ellipsoidal=None): 

385 '''Is B{C{obj}}ect some C{Nvector}? 

386 

387 @arg obj: The object (any C{type}). 

388 @kwarg ellipsoidal: If C{None}, return the type of any C{Nvector}, 

389 if C{True}, only an ellipsoidal C{Nvector type} 

390 or if C{False}, only a spherical C{Nvector type}. 

391 

392 @return: C{type(B{obj}} if an C{Nvector} of the required type, C{False} 

393 if an C{Nvector} of an other type or {None} otherwise. 

394 ''' 

395 if ellipsoidal is not None: 

396 try: 

397 return obj.ellipsoidalNvector if ellipsoidal else obj.sphericalNvector 

398 except AttributeError: 

399 return None 

400 return isinstanceof(obj, _MODS.nvectorBase.NvectorBase) 

401 

402 

403def isodd(x): 

404 '''Is B{C{x}} odd? 

405 

406 @arg x: Value (C{scalar}). 

407 

408 @return: C{True} if odd, C{False} otherwise. 

409 ''' 

410 return bool(int(x) & 1) # == bool(int(x) % 2) 

411 

412 

413def isscalar(obj, both=False): 

414 '''Is B{C{obj}}ect an C{int} or integer C{float} value? 

415 

416 @arg obj: The object (any C{type}). 

417 @kwarg both: If C{True}, check L{Fsum<Fsum.residual>}. 

418 

419 @return: C{True} if C{int}, C{float} or L{Fsum} with 

420 zero residual, C{False} otherwise. 

421 ''' 

422 if isinstance(obj, _Scalars): 

423 return not isbool(obj) 

424 elif both: # and isinstance(obj, Fsum) 

425 try: 

426 return bool(obj.residual == 0) 

427 except (AttributeError, TypeError): 

428 pass # XXX float(int(obj)) == obj? 

429 return False 

430 

431 

432def issequence(obj, *excls): 

433 '''Is B{C{obj}}ect some sequence type? 

434 

435 @arg obj: The object (any C{type}). 

436 @arg excls: Classes to exclude (C{type}), all positional. 

437 

438 @note: Excluding C{tuple} implies excluding C{namedtuple}. 

439 

440 @return: C{True} if a sequence, C{False} otherwise. 

441 ''' 

442 return isinstance(obj, _Seqs) and not (excls and isinstance(obj, excls)) 

443 

444 

445def isstr(obj): 

446 '''Is B{C{obj}}ect some string type? 

447 

448 @arg obj: The object (any C{type}). 

449 

450 @return: C{True} if a C{str}, C{bytes}, ..., 

451 C{False} otherwise. 

452 ''' 

453 return isinstance(obj, _Strs) 

454 

455 

456def issubclassof(Sub, *Supers): 

457 '''Is B{C{Sub}} a class and sub-class of some other class(es)? 

458 

459 @arg Sub: The sub-class (C{Class}). 

460 @arg Supers: One or more C(super) classes (C{Class}). 

461 

462 @return: C{True} if a sub-class of any B{C{Supers}}, C{False} 

463 if not (C{bool}) or C{None} if not a class or if no 

464 B{C{Supers}} are given or none of those are a class. 

465 ''' 

466 if isclass(Sub): 

467 t = tuple(S for S in Supers if isclass(S)) 

468 if t: 

469 return bool(issubclass(Sub, t)) 

470 return None 

471 

472 

473def itemsorted(adict, *items_args, **asorted_reverse): 

474 '''Return the items of C{B{adict}} sorted I{alphabetically, 

475 case-insensitively} and in I{ascending} order. 

476 

477 @arg items_args: Optional positional argument(s) for method 

478 C{B{adict}.items(B*{items_args})}. 

479 @kwarg asorted_reverse: Use C{B{asorted}=False} for I{alphabetical, 

480 case-sensitive} sorting and C{B{reverse}=True} for 

481 sorting in C{descending} order. 

482 ''' 

483 def _ins(item): # functools.cmp_to_key 

484 k, v = item 

485 return k.lower() 

486 

487 def _reverse_key(asorted=True, reverse=False): 

488 return dict(reverse=reverse, key=_ins if asorted else None) 

489 

490 items = adict.items(*items_args) if items_args else adict.items() 

491 return sorted(items, **_reverse_key(**asorted_reverse)) 

492 

493 

494def len2(items): 

495 '''Make built-in function L{len} work for generators, iterators, 

496 etc. since those can only be started exactly once. 

497 

498 @arg items: Generator, iterator, list, range, tuple, etc. 

499 

500 @return: 2-Tuple C{(n, items)} of the number of items (C{int}) 

501 and the items (C{list} or C{tuple}). 

502 ''' 

503 if not isinstance(items, _Seqs): # NOT hasattr(items, '__len__'): 

504 items = list(items) 

505 return len(items), items 

506 

507 

508def map1(fun1, *xs): # XXX map_ 

509 '''Call a single-argument function to each B{C{xs}} 

510 and return a C{tuple} of results. 

511 

512 @arg fun1: 1-Arg function (C{callable}). 

513 @arg xs: Arguments (C{any positional}). 

514 

515 @return: Function results (C{tuple}). 

516 ''' 

517 return tuple(map(fun1, xs)) 

518 

519 

520def map2(fun, *xs): 

521 '''Like Python's B{C{map}} but returning a C{tuple} of results. 

522 

523 Unlike Python 2's built-in L{map}, Python 3+ L{map} returns a 

524 L{map} object, an iterator-like object which generates the 

525 results only once. Converting the L{map} object to a tuple 

526 maintains the Python 2 behavior. 

527 

528 @arg fun: Function (C{callable}). 

529 @arg xs: Arguments (C{all positional}). 

530 

531 @return: Function results (C{tuple}). 

532 ''' 

533 return tuple(map(fun, *xs)) 

534 

535 

536def neg(x, neg0=None): 

537 '''Negate C{x} and optionally, negate C{0.0} and C{-0.0}. 

538 

539 @kwarg neg0: Defines the return value for zero C{B{x}}: if C{None} 

540 return C{0.0}, if C{True} return C{NEG0 if B{x}=0.0} 

541 and C{0.0 if B{x}=NEG0} or if C{False} return C{B{x}} 

542 I{as-is} (C{bool} or C{None}). 

543 

544 @return: C{-B{x} if B{x} else 0.0, NEG0 or B{x}}. 

545 ''' 

546 return (-x) if x else ( 

547 _0_0 if neg0 is None else ( 

548 x if not neg0 else ( 

549 _0_0 if signBit(x) else _MODS.constants. 

550 NEG0))) # PYCHOK indent 

551 

552 

553def neg_(*xs): 

554 '''Negate all C{xs} with L{neg}. 

555 

556 @return: A C{map(neg, B{xs})}. 

557 ''' 

558 return map(neg, xs) 

559 

560 

561def _neg0(x): 

562 '''(INTERNAL) Return C{NEG0 if x < 0 else _0_0}, 

563 unlike C{_copysign_0_0} which returns C{_N_0_0}. 

564 ''' 

565 return _MODS.constants.NEG0 if x < 0 else _0_0 

566 

567 

568def _req_d_by(where, **name): 

569 '''(INTERNAL) Get the fully qualified name. 

570 ''' 

571 m = _MODS.named 

572 n = m._name__(**name) 

573 m = m.modulename(where, prefixed=True) 

574 if n: 

575 m = _DOT_(m, n) 

576 return _SPACE_(_required_, _by_, m) 

577 

578 

579def _reverange(n, stop=-1, step=-1): 

580 '''(INTERNAL) Reversed range yielding C{n-1, n-1-step, ..., stop+1}. 

581 ''' 

582 return range(n - 1, stop, step) 

583 

584 

585def signBit(x): 

586 '''Return C{signbit(B{x})}, like C++. 

587 

588 @return: C{True} if C{B{x} < 0} or C{NEG0} (C{bool}). 

589 ''' 

590 return x < 0 or _MODS.constants.isneg0(x) 

591 

592 

593def _signOf(x, ref): # in .fsums 

594 '''(INTERNAL) Return the sign of B{C{x}} versus B{C{ref}}. 

595 ''' 

596 return (-1) if x < ref else (+1 if x > ref else 0) 

597 

598 

599def signOf(x): 

600 '''Return sign of C{x} as C{int}. 

601 

602 @return: -1, 0 or +1 (C{int}). 

603 ''' 

604 try: 

605 s = x.signOf() # Fsum instance? 

606 except AttributeError: 

607 s = _signOf(x, 0) 

608 return s 

609 

610 

611def splice(iterable, n=2, **fill): 

612 '''Split an iterable into C{n} slices. 

613 

614 @arg iterable: Items to be spliced (C{list}, C{tuple}, ...). 

615 @kwarg n: Number of slices to generate (C{int}). 

616 @kwarg fill: Optional fill value for missing items. 

617 

618 @return: A generator for each of B{C{n}} slices, 

619 M{iterable[i::n] for i=0..n}. 

620 

621 @raise TypeError: Invalid B{C{n}}. 

622 

623 @note: Each generated slice is a C{tuple} or a C{list}, 

624 the latter only if the B{C{iterable}} is a C{list}. 

625 

626 @example: 

627 

628 >>> from pygeodesy import splice 

629 

630 >>> a, b = splice(range(10)) 

631 >>> a, b 

632 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9)) 

633 

634 >>> a, b, c = splice(range(10), n=3) 

635 >>> a, b, c 

636 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8)) 

637 

638 >>> a, b, c = splice(range(10), n=3, fill=-1) 

639 >>> a, b, c 

640 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1)) 

641 

642 >>> tuple(splice(list(range(9)), n=5)) 

643 ([0, 5], [1, 6], [2, 7], [3, 8], [4]) 

644 

645 >>> splice(range(9), n=1) 

646 <generator object splice at 0x0...> 

647 ''' 

648 if not isint(n): 

649 raise _TypeError(n=n) 

650 

651 t = _xiterablen(iterable) 

652 if not isinstance(t, _list_tuple_types): 

653 t = tuple(t) 

654 

655 if n > 1: 

656 if fill: 

657 fill = _xkwds_get(fill, fill=MISSING) 

658 if fill is not MISSING: 

659 m = len(t) % n 

660 if m > 0: # same type fill 

661 t = t + type(t)((fill,) * (n - m)) 

662 for i in range(n): 

663 # XXX t[i::n] chokes PyChecker 

664 yield t[slice(i, None, n)] 

665 else: 

666 yield t # 1 slice, all 

667 

668 

669def _splituple(strs, *sep_splits): # in .mgrs, .osgr, .webmercator 

670 '''(INTERNAL) Split a C{comma}- or C{whitespace}-separated 

671 string into a C{tuple} of stripped strings. 

672 ''' 

673 t = (strs.split(*sep_splits) if sep_splits else 

674 strs.replace(_COMMA_, _SPACE_).split()) if strs else () 

675 return tuple(s.strip() for s in t if s) 

676 

677 

678def unsigned0(x): 

679 '''Unsign if C{0.0}. 

680 

681 @return: C{B{x}} if B{C{x}} else C{0.0}. 

682 ''' 

683 return x if x else _0_0 

684 

685 

686def _xcopy(obj, deep=False): 

687 '''(INTERNAL) Copy an object, shallow or deep. 

688 

689 @arg obj: The object to copy (any C{type}). 

690 @kwarg deep: If C{True} make a deep, otherwise 

691 a shallow copy (C{bool}). 

692 

693 @return: The copy of B{C{obj}}. 

694 ''' 

695 return _deepcopy(obj) if deep else _copy(obj) 

696 

697 

698def _xdup(obj, deep=False, **items): 

699 '''(INTERNAL) Duplicate an object, replacing some attributes. 

700 

701 @arg obj: The object to copy (any C{type}). 

702 @kwarg deep: If C{True} copy deep, otherwise shallow. 

703 @kwarg items: Attributes to be changed (C{any}). 

704 

705 @return: A duplicate of B{C{obj}} with modified 

706 attributes, if any B{C{items}}. 

707 

708 @raise AttributeError: Some B{C{items}} invalid. 

709 ''' 

710 d = _xcopy(obj, deep=deep) 

711 for n, v in items.items(): 

712 if getattr(d, n, v) != v: 

713 setattr(d, n, v) 

714 elif not hasattr(d, n): 

715 t = _MODS.named.classname(obj) 

716 t = _SPACE_(_DOT_(t, n), _invalid_) 

717 raise _AttributeError(txt=t, obj=obj, **items) 

718# if items: 

719# _MODS.props._update_all(d) 

720 return d 

721 

722 

723def _xgeographiclib(where, *required): 

724 '''(INTERNAL) Import C{geographiclib} and check required version. 

725 ''' 

726 try: 

727 _xpackage(_xgeographiclib) 

728 import geographiclib 

729 except ImportError as x: 

730 raise _xImportError(x, where, Error=LazyImportError) 

731 return _xversion(geographiclib, where, *required) 

732 

733 

734def _xImportError(exc, where, Error=_ImportError, **name): 

735 '''(INTERNAL) Embellish an C{Lazy/ImportError}. 

736 ''' 

737 t = _req_d_by(where, **name) 

738 return Error(_Xstr(exc), txt=t, cause=exc) 

739 

740 

741def _xinstanceof(*Types, **names_values): 

742 '''(INTERNAL) Check C{Types} of all C{name=value} pairs. 

743 

744 @arg Types: One or more classes or types (C{class}), all 

745 positional. 

746 @kwarg names_values: One or more C{B{name}=value} pairs 

747 with the C{value} to be checked. 

748 

749 @raise TypeError: One B{C{names_values}} pair is not an 

750 instance of any of the B{C{Types}}. 

751 ''' 

752 if not (Types and names_values): 

753 raise _xAssertionError(_xinstanceof, *Types, **names_values) 

754 

755 for n, v in names_values.items(): 

756 if not isinstance(v, Types): 

757 raise _TypesError(n, v, *Types) 

758 

759 

760def _xiterable(obj): 

761 '''(INTERNAL) Return C{obj} if iterable, otherwise raise C{TypeError}. 

762 ''' 

763 return obj if isiterable(obj) else _xiterror(obj, _xiterable) # PYCHOK None 

764 

765 

766def _xiterablen(obj): 

767 '''(INTERNAL) Return C{obj} if iterable with C{__len__}, otherwise raise C{TypeError}. 

768 ''' 

769 return obj if isiterablen(obj) else _xiterror(obj, _xiterablen) # PYCHOK None 

770 

771 

772def _xiterror(obj, _xwhich): 

773 '''(INTERNAL) Helper for C{_xinterable} and C{_xiterablen}. 

774 ''' 

775 t = _not_(_xwhich.__name__[2:]) # _dunder_nameof 

776 raise _TypeError(repr(obj), txt=t) 

777 

778 

779def _xnumpy(where, *required): 

780 '''(INTERNAL) Import C{numpy} and check required version. 

781 ''' 

782 try: 

783 _xpackage(_xnumpy) 

784 import numpy 

785 except ImportError as x: 

786 raise _xImportError(x, where) 

787 return _xversion(numpy, where, *required) 

788 

789 

790def _xor(x, *xs): 

791 '''(INTERNAL) Exclusive-or C{x} and C{xs}. 

792 ''' 

793 for x_ in xs: 

794 x ^= x_ 

795 return x 

796 

797 

798def _xpackage(_xpkg): 

799 '''(INTERNAL) Check dependency to be excluded. 

800 ''' 

801 n = _xpkg.__name__[2:] # _dunder_nameof 

802 if n in _XPACKAGES: 

803 x = _SPACE_(n, _in_, _PYGEODESY_XPACKAGES_) 

804 e = _enquote(_getenv(_PYGEODESY_XPACKAGES_, NN)) 

805 raise ImportError(_EQUAL_(x, e)) 

806 

807 

808def _xscalar(**names_values): 

809 '''(INTERNAL) Check all C{name=value} pairs to be C{scalar}. 

810 ''' 

811 for n, v in names_values.items(): 

812 if not isscalar(v): 

813 raise _TypeError(n, v, txt=_not_scalar_) 

814 

815 

816def _xscipy(where, *required): 

817 '''(INTERNAL) Import C{scipy} and check required version. 

818 ''' 

819 try: 

820 _xpackage(_xscipy) 

821 import scipy 

822 except ImportError as x: 

823 raise _xImportError(x, where) 

824 return _xversion(scipy, where, *required) 

825 

826 

827def _xsubclassof(*Classes, **names_values): 

828 '''(INTERNAL) Check (super) class of all C{name=value} pairs. 

829 

830 @arg Classes: One or more classes or types (C{class}), all 

831 positional. 

832 @kwarg names_values: One or more C{B{name}=value} pairs 

833 with the C{value} to be checked. 

834 

835 @raise TypeError: One B{C{names_values}} pair is not a 

836 (sub-)class of any of the B{C{Classes}}. 

837 ''' 

838 if not (Classes and names_values): 

839 raise _xAssertionError(_xsubclassof, *Classes, **names_values) 

840 

841 for n, v in names_values.items(): 

842 if not issubclassof(v, *Classes): 

843 raise _TypesError(n, v, *Classes) 

844 

845 

846def _xversion(package, where, *required, **name): 

847 '''(INTERNAL) Check the C{package} version vs B{C{required}}. 

848 ''' 

849 if required: 

850 t = _version_info(package) 

851 if t[:len(required)] < required: 

852 t = _SPACE_(package.__name__, # _dunder_nameof 

853 _version_, _DOT_(*t), 

854 _below_, _DOT_(*required), 

855 _req_d_by(where, **name)) 

856 raise ImportError(t) 

857 return package 

858 

859 

860def _xzip(*args, **strict): # PYCHOK no cover 

861 '''(INTERNAL) Standard C{zip(..., strict=True)}. 

862 ''' 

863 s = _xkwds_get(strict, strict=True) 

864 if s: 

865 if _zip is zip: # < (3, 10) 

866 t = _MODS.streprs.unstr(_xzip, *args, strict=s) 

867 raise _NotImplementedError(t, txt=None) 

868 return _zip(*args) 

869 return zip(*args) 

870 

871 

872if _sys_version_info2 < (3, 10): # see .errors 

873 _zip = zip # PYCHOK exported 

874else: # Python 3.10+ 

875 

876 def _zip(*args): 

877 return zip(*args, strict=True) 

878 

879_XPACKAGES = _splituple(_getenv(_PYGEODESY_XPACKAGES_, NN).lower()) 

880 

881# **) MIT License 

882# 

883# Copyright (C) 2016-2024 -- mrJean1 at Gmail -- All Rights Reserved. 

884# 

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

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

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

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

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

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

891# 

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

893# in all copies or substantial portions of the Software. 

894# 

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

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

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

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

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

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

901# OTHER DEALINGS IN THE SOFTWARE.