Coverage for pygeodesy/basics.py: 89%

262 statements  

« prev     ^ index     » next       coverage.py v7.2.2, created at 2024-06-10 14:08 -0400

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_get1 

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__ = '24.05.29' 

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_count2(func, exelf=True): 

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 try: 

122 a = k = 0 

123 for _, p in _inspect.signature(func).parameters.items(): 

124 if p.kind is p.POSITIONAL_OR_KEYWORD: 

125 if p.default is p.empty: 

126 a += 1 

127 else: 

128 k += 1 

129 except AttributeError: # .signature new Python 3+ 

130 s = _inspect.getargspec(func) 

131 k = len(s.defaults or ()) 

132 a = len(s.args) - k 

133 if exelf and a > 0 and _inspect.ismethod(func): 

134 a -= 1 

135 return a, k 

136 

137 

138def _args_kwds_names(func, splast=False): 

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

140 C{self} for methods. 

141 

142 @kwarg splast: If C{True}, split the last keyword argument 

143 at UNDERscores (C{bool}). 

144 

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

146 C{**kwds} names. 

147 ''' 

148 try: 

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

150 except AttributeError: # .signature new Python 3+ 

151 args_kwds = _inspect.getargspec(func).args 

152 if splast and args_kwds: 

153 args_kwds = list(args_kwds) 

154 t = args_kwds[-1:] 

155 if t: 

156 s = t[0].strip(_UNDER_).split(_UNDER_) 

157 if len(s) > 1 or s != t: 

158 args_kwds += s 

159 return tuple(args_kwds) 

160 

161 

162def clips(sb, limit=50, white=NN): 

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

164 

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

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

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

168 

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

170 ''' 

171 T = type(sb) 

172 if len(sb) > limit > 8: 

173 h = limit // 2 

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

175 if white: # replace whitespace 

176 sb = T(white).join(sb.split()) 

177 return sb 

178 

179 

180def copysign0(x, y): 

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

182 

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

184 C{type(B{x})(0)}. 

185 ''' 

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

187 

188 

189def copytype(x, y): 

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

191 

192 @return: C{type(B{y})(B{x})}. 

193 ''' 

194 return type(y)(x if x else _0_0) 

195 

196 

197def halfs2(str2): 

198 '''Split a string in 2 halfs. 

199 

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

201 

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

203 

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

205 ''' 

206 h, r = divmod(len(str2), 2) 

207 if r or not h: 

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

209 return str2[:h], str2[h:] 

210 

211 

212def int1s(x): 

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

214 

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

216 ''' 

217 try: 

218 return x.bit_count() # Python 3.10+ 

219 except AttributeError: 

220 # bin(-x) = '-' + bin(abs(x)) 

221 return bin(x).count(_1_) 

222 

223 

224def isbool(obj): 

225 '''Is B{C{obj}}ect a C{bool}ean? 

226 

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

228 

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

230 ''' 

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

232# or obj is True) 

233 

234assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2 

235 

236 

237def isCartesian(obj, ellipsoidal=None): 

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

239 

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

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

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

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

244 

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

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

247 ''' 

248 if ellipsoidal is not None: 

249 try: 

250 return obj.ellipsoidalCartesian if ellipsoidal else obj.sphericalCartesian 

251 except AttributeError: 

252 return None 

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

254 

255 

256if _FOR_DOCS: # XXX avoid epydoc Python 2.7 error 

257 

258 def isclass(obj): 

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

260 ''' 

261 return _inspect.isclass(obj) 

262else: 

263 isclass = _inspect.isclass 

264 

265 

266def iscomplex(obj, both=False): 

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

268 

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

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

271 

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

273 ''' 

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

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

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

277 except (TypeError, ValueError): 

278 return False 

279 

280 

281def isDEPRECATED(obj): 

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

283 

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

285 C{None} if undetermined. 

286 ''' 

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

288 doc = obj.__doc__.lstrip() 

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

290 except AttributeError: 

291 return None 

292 

293 

294def isfloat(obj, both=False): 

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

296 

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

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

299 

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

301 ''' 

302 try: 

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

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

305 except (TypeError, ValueError): 

306 return False 

307 

308 

309try: 

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

311except AttributeError: # Python 2- 

312 

313 def isidentifier(obj): 

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

315 ''' 

316 return bool(obj and isstr(obj) 

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

318 and not obj[:1].isdigit()) 

319 

320 

321def isinstanceof(obj, *Classes): 

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

323 

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

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

326 

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

328 C{None} otherwise. 

329 ''' 

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

331 

332 

333def isint(obj, both=False): 

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

335 

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

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

338 type and value (C{bool}). 

339 

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

341 or L{Fsum}, C{False} otherwise. 

342 

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

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

345 ''' 

346 if isinstance(obj, _Ints): 

347 return not isbool(obj) 

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

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

350 return obj.is_integer() 

351 except AttributeError: 

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

353 return False 

354 

355 

356def isiterable(obj): 

357 '''Is B{C{obj}}ect C{iterable}? 

358 

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

360 

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

362 ''' 

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

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

365 

366 

367def isiterablen(obj): 

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

369 

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

371 

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

373 ''' 

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

375 

376 

377try: 

378 from keyword import iskeyword # Python 2.7+ 

379except ImportError: 

380 

381 def iskeyword(unused): 

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

383 ''' 

384 return False 

385 

386 

387def isLatLon(obj, ellipsoidal=None): 

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

389 

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

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

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

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

394 

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

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

397 ''' 

398 if ellipsoidal is not None: 

399 try: 

400 return obj.ellipsoidalLatLon if ellipsoidal else obj.sphericalLatLon 

401 except AttributeError: 

402 return None 

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

404 

405 

406def islistuple(obj, minum=0): 

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

408 

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

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

411 

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

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

414 ''' 

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

416 

417 

418def isNvector(obj, ellipsoidal=None): 

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

420 

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

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

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

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

425 

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

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

428 ''' 

429 if ellipsoidal is not None: 

430 try: 

431 return obj.ellipsoidalNvector if ellipsoidal else obj.sphericalNvector 

432 except AttributeError: 

433 return None 

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

435 

436 

437def isodd(x): 

438 '''Is B{C{x}} odd? 

439 

440 @arg x: Value (C{scalar}). 

441 

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

443 ''' 

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

445 

446 

447def isscalar(obj, both=False): 

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

449 

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

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

452 

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

454 zero residual, C{False} otherwise. 

455 ''' 

456 if isinstance(obj, _Scalars): 

457 return not isbool(obj) 

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

459 try: 

460 return bool(obj.residual == 0) 

461 except (AttributeError, TypeError): 

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

463 return False 

464 

465 

466def issequence(obj, *excls): 

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

468 

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

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

471 

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

473 

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

475 ''' 

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

477 

478 

479def isstr(obj): 

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

481 

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

483 

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

485 C{False} otherwise. 

486 ''' 

487 return isinstance(obj, _Strs) 

488 

489 

490def issubclassof(Sub, *Supers): 

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

492 

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

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

495 

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

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

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

499 ''' 

500 if isclass(Sub): 

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

502 if t: 

503 return bool(issubclass(Sub, t)) 

504 return None 

505 

506 

507def itemsorted(adict, *items_args, **asorted_reverse): 

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

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

510 

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

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

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

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

515 sorting in C{descending} order. 

516 ''' 

517 def _ins(item): # functools.cmp_to_key 

518 k, v = item 

519 return k.lower() 

520 

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

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

523 

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

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

526 

527 

528def len2(items): 

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

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

531 

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

533 

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

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

536 ''' 

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

538 items = list(items) 

539 return len(items), items 

540 

541 

542def map1(fun1, *xs): # XXX map_ 

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

544 and return a C{tuple} of results. 

545 

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

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

548 

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

550 ''' 

551 return tuple(map(fun1, xs)) 

552 

553 

554def map2(fun, *xs): 

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

556 

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

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

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

560 maintains the Python 2 behavior. 

561 

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

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

564 

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

566 ''' 

567 return tuple(map(fun, *xs)) 

568 

569 

570def neg(x, neg0=None): 

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

572 

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

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

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

576 I{as-is} (C{bool} or C{None}). 

577 

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

579 ''' 

580 return (-x) if x else ( 

581 _0_0 if neg0 is None else ( 

582 x if not neg0 else ( 

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

584 NEG0))) # PYCHOK indent 

585 

586 

587def neg_(*xs): 

588 '''Negate all C{xs} with L{neg}. 

589 

590 @return: A C{map(neg, B{xs})}. 

591 ''' 

592 return map(neg, xs) 

593 

594 

595def _neg0(x): 

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

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

598 ''' 

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

600 

601 

602def _req_d_by(where, **name): 

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

604 ''' 

605 m = _MODS.named 

606 n = m._name__(**name) 

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

608 if n: 

609 m = _DOT_(m, n) 

610 return _SPACE_(_required_, _by_, m) 

611 

612 

613def _reverange(n, stop=-1, step=-1): 

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

615 ''' 

616 return range(n - 1, stop, step) 

617 

618 

619def signBit(x): 

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

621 

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

623 ''' 

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

625 

626 

627def _signOf(x, ref): # in .fsums 

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

629 ''' 

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

631 

632 

633def signOf(x): 

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

635 

636 @return: -1, 0 or +1 (C{int}). 

637 ''' 

638 try: 

639 s = x.signOf() # Fsum instance? 

640 except AttributeError: 

641 s = _signOf(x, 0) 

642 return s 

643 

644 

645def splice(iterable, n=2, **fill): 

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

647 

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

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

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

651 

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

653 M{iterable[i::n] for i=0..n}. 

654 

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

656 

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

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

659 

660 @example: 

661 

662 >>> from pygeodesy import splice 

663 

664 >>> a, b = splice(range(10)) 

665 >>> a, b 

666 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9)) 

667 

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

669 >>> a, b, c 

670 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8)) 

671 

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

673 >>> a, b, c 

674 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1)) 

675 

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

677 ([0, 5], [1, 6], [2, 7], [3, 8], [4]) 

678 

679 >>> splice(range(9), n=1) 

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

681 ''' 

682 if not isint(n): 

683 raise _TypeError(n=n) 

684 

685 t = _xiterablen(iterable) 

686 if not isinstance(t, _list_tuple_types): 

687 t = tuple(t) 

688 

689 if n > 1: 

690 if fill: 

691 fill = _xkwds_get1(fill, fill=MISSING) 

692 if fill is not MISSING: 

693 m = len(t) % n 

694 if m > 0: # same type fill 

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

696 for i in range(n): 

697 # XXX t[i::n] chokes PyChecker 

698 yield t[slice(i, None, n)] 

699 else: 

700 yield t # 1 slice, all 

701 

702 

703def _splituple(strs, *sep_splits): # in .mgrs, .osgr, .webmercator 

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

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

706 ''' 

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

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

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

710 

711 

712def unsigned0(x): 

713 '''Unsign if C{0.0}. 

714 

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

716 ''' 

717 return x if x else _0_0 

718 

719 

720def _xcopy(obj, deep=False): 

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

722 

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

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

725 a shallow copy (C{bool}). 

726 

727 @return: The copy of B{C{obj}}. 

728 ''' 

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

730 

731 

732def _xdup(obj, deep=False, **items): 

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

734 

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

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

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

738 

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

740 attributes, if any B{C{items}}. 

741 

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

743 ''' 

744 d = _xcopy(obj, deep=deep) 

745 for n, v in items.items(): 

746 if getattr(d, n, v) != v: 

747 setattr(d, n, v) 

748 elif not hasattr(d, n): 

749 t = _MODS.named.classname(obj) 

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

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

752# if items: 

753# _MODS.props._update_all(d) 

754 return d 

755 

756 

757def _xgeographiclib(where, *required): 

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

759 ''' 

760 try: 

761 _xpackage(_xgeographiclib) 

762 import geographiclib 

763 except ImportError as x: 

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

765 return _xversion(geographiclib, where, *required) 

766 

767 

768def _xImportError(exc, where, Error=_ImportError, **name): 

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

770 ''' 

771 t = _req_d_by(where, **name) 

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

773 

774 

775def _xinstanceof(*Types, **names_values): 

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

777 

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

779 positional. 

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

781 with the C{value} to be checked. 

782 

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

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

785 ''' 

786 if not (Types and names_values): 

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

788 

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

790 if not isinstance(v, Types): 

791 raise _TypesError(n, v, *Types) 

792 

793 

794def _xiterable(obj): 

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

796 ''' 

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

798 

799 

800def _xiterablen(obj): 

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

802 ''' 

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

804 

805 

806def _xiterror(obj, _xwhich): 

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

808 ''' 

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

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

811 

812 

813def _xnumpy(where, *required): 

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

815 ''' 

816 try: 

817 _xpackage(_xnumpy) 

818 import numpy 

819 except ImportError as x: 

820 raise _xImportError(x, where) 

821 return _xversion(numpy, where, *required) 

822 

823 

824def _xor(x, *xs): 

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

826 ''' 

827 for x_ in xs: 

828 x ^= x_ 

829 return x 

830 

831 

832def _xpackage(_xpkg): 

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

834 ''' 

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

836 if n in _XPACKAGES: 

837 x = _SPACE_(n, _in_, _PYGEODESY_XPACKAGES_) 

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

839 raise ImportError(_EQUAL_(x, e)) 

840 

841 

842def _xscalar(**names_values): 

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

844 ''' 

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

846 if not isscalar(v): 

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

848 

849 

850def _xscipy(where, *required): 

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

852 ''' 

853 try: 

854 _xpackage(_xscipy) 

855 import scipy 

856 except ImportError as x: 

857 raise _xImportError(x, where) 

858 return _xversion(scipy, where, *required) 

859 

860 

861def _xsubclassof(*Classes, **names_values): 

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

863 

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

865 positional. 

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

867 with the C{value} to be checked. 

868 

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

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

871 ''' 

872 if not (Classes and names_values): 

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

874 

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

876 if not issubclassof(v, *Classes): 

877 raise _TypesError(n, v, *Classes) 

878 

879 

880def _xversion(package, where, *required, **name): 

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

882 ''' 

883 if required: 

884 t = _version_info(package) 

885 if t[:len(required)] < required: 

886 t = _SPACE_(package.__name__, # _dunder_nameof 

887 _version_, _DOT_(*t), 

888 _below_, _DOT_(*required), 

889 _req_d_by(where, **name)) 

890 raise ImportError(t) 

891 return package 

892 

893 

894def _xzip(*args, **strict): # PYCHOK no cover 

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

896 ''' 

897 s = _xkwds_get1(strict, strict=True) 

898 if s: 

899 if _zip is zip: # < (3, 10) 

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

901 raise _NotImplementedError(t, txt=None) 

902 return _zip(*args) 

903 return zip(*args) 

904 

905 

906if _sys_version_info2 < (3, 10): # see .errors 

907 _zip = zip # PYCHOK exported 

908else: # Python 3.10+ 

909 

910 def _zip(*args): 

911 return zip(*args, strict=True) 

912 

913_XPACKAGES = _splituple(_getenv(_PYGEODESY_XPACKAGES_, NN).lower()) 

914 

915# **) MIT License 

916# 

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

918# 

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

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

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

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

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

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

925# 

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

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

928# 

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

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

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

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

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

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

935# OTHER DEALINGS IN THE SOFTWARE.