Coverage for pygeodesy/basics.py: 91%

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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_get1 

22# from pygeodesy.fsums import _isFsum_2Tuple # _MODS 

23from pygeodesy.internals import _0_0, _enquote, _passarg, _version_info 

24from pygeodesy.interns import MISSING, NN, _1_, _by_, _COMMA_, _DOT_, _DEPRECATED_, \ 

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

26 _not_scalar_, _odd_, _SPACE_, _UNDER_, _version_ 

27# from pygeodesy.latlonBase import LatLonBase # _MODS 

28from pygeodesy.lazily import _ALL_LAZY, _ALL_MODS as _MODS, _FOR_DOCS, _getenv, \ 

29 LazyImportError, _sys_version_info2 

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 

34# from pygeodesy.unitsBase import _NamedUnit, Str # _MODS 

35 

36from copy import copy as _copy, deepcopy as _deepcopy 

37from math import copysign as _copysign 

38import inspect as _inspect 

39 

40__all__ = _ALL_LAZY.basics 

41__version__ = '24.09.28' 

42 

43_below_ = 'below' 

44_list_tuple_types = (list, tuple) 

45_PYGEODESY_XPACKAGES_ = 'PYGEODESY_XPACKAGES' 

46_required_ = 'required' 

47 

48try: # Luciano Ramalho, "Fluent Python", O'Reilly, 2016 p. 395, 2022 p. 577+ 

49 from numbers import Integral as _Ints, Real as _Scalars # .units 

50except ImportError: 

51 try: 

52 _Ints = int, long # int objects (C{tuple}) 

53 except NameError: # Python 3+ 

54 _Ints = int, # int objects (C{tuple}) 

55 _Scalars = (float,) + _Ints 

56 

57try: 

58 try: # use C{from collections.abc import ...} in Python 3.9+ 

59 from collections.abc import Sequence as _Sequence # in .points 

60 except ImportError: # no .abc in Python 3.8- and 2.7- 

61 from collections import Sequence as _Sequence # in .points 

62 if isinstance([], _Sequence) and isinstance((), _Sequence): 

63 # and isinstance(range(1), _Sequence): 

64 _Seqs = _Sequence 

65 else: 

66 raise ImportError() # _AssertionError 

67except ImportError: 

68 _Sequence = tuple # immutable for .points._Basequence 

69 _Seqs = list, _Sequence # range for function len2 below 

70 

71try: 

72 _Bytes = unicode, bytearray # PYCHOK in .internals 

73 _Strs = basestring, str # XXX str == bytes 

74 str2ub = ub2str = _passarg # avoids UnicodeDecodeError 

75 

76 def _Xstr(exc): # PYCHOK no cover 

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

78 

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

80 

81 only for C{numpy}, C{scipy} import errors occurring 

82 on arm64 Apple Silicon running macOS' Python 2.7.16? 

83 ''' 

84 t = str(exc) 

85 if '_distributor_init' in t: 

86 from sys import exc_info 

87 from traceback import extract_tb 

88 tb = exc_info()[2] # 3-tuple (type, value, traceback) 

89 t4 = extract_tb(tb, 1)[0] # 4-tuple (file, line, name, 'import ...') 

90 t = _SPACE_("can't", t4[3] or _N_A_) 

91 del tb, t4 

92 return t 

93 

94except NameError: # Python 3+ 

95 from pygeodesy.interns import _utf_8_ 

96 

97 _Bytes = bytes, bytearray # in .internals 

98 _Strs = str, # tuple 

99 _Xstr = str 

100 

101 def str2ub(sb): 

102 '''Convert C{str} to C{unicode bytes}. 

103 ''' 

104 if isinstance(sb, _Strs): 

105 sb = sb.encode(_utf_8_) 

106 return sb 

107 

108 def ub2str(ub): 

109 '''Convert C{unicode bytes} to C{str}. 

110 ''' 

111 if isinstance(ub, _Bytes): 

112 ub = str(ub.decode(_utf_8_)) 

113 return ub 

114 

115 

116def _args_kwds_count2(func, exelf=True): 

117 '''(INTERNAL) Get a C{func}'s args and kwds count as 2-tuple 

118 C{(nargs, nkwds)}, including arg C{self} for methods. 

119 

120 @kwarg exelf: If C{True}, exclude C{self} in the C{args} 

121 of a method (C{bool}). 

122 ''' 

123 try: # PYCHOK no cover 

124 a = k = 0 

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

126 if p.kind is p.POSITIONAL_OR_KEYWORD: 

127 if p.default is p.empty: 

128 a += 1 

129 else: 

130 k += 1 

131 except AttributeError: # .signature new Python 3+ 

132 s = _inspect.getargspec(func) 

133 k = len(s.defaults or ()) 

134 a = len(s.args) - k 

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

136 a -= 1 

137 return a, k 

138 

139 

140def _args_kwds_names(func, splast=False): 

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

142 C{self} for methods. 

143 

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

145 at UNDERscores (C{bool}). 

146 

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

148 C{**kwds} names. 

149 ''' 

150 try: 

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

152 except AttributeError: # .signature new Python 3+ 

153 args_kwds = _inspect.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) 

162 

163 

164def clips(sb, limit=50, white=NN, length=False): 

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

166 

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}). 

171 

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 

184 

185 

186def copysign0(x, y): 

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

188 

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) 

193 

194 

195def copytype(x, y): 

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

197 

198 @return: C{type(B{y})(B{x})}. 

199 ''' 

200 return type(y)(x if x else _0_0) 

201 

202 

203def _enumereverse(iterable): 

204 '''(INTERNAL) Reversed C{enumberate}. 

205 ''' 

206 for j in _reverange(len(iterable)): 

207 yield j, iterable[j] 

208 

209 

210def halfs2(str2): 

211 '''Split a string in 2 halfs. 

212 

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

214 

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

216 

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:] 

223 

224 

225def int1s(x): 

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

227 

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_) 

235 

236 

237def isbool(obj): 

238 '''Is B{C{obj}}ect a C{bool}ean? 

239 

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

241 

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) 

246 

247assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2 

248 

249 

250def isCartesian(obj, ellipsoidal=None): 

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

252 

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}. 

257 

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) 

267 

268 

269if _FOR_DOCS: # XXX avoid epydoc Python 2.7 error 

270 

271 def isclass(obj): 

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

273 ''' 

274 return _inspect.isclass(obj) 

275else: 

276 isclass = _inspect.isclass 

277 

278 

279def iscomplex(obj, both=False): 

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

281 

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

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

284 

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

286 ''' 

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

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

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

290 except (TypeError, ValueError): 

291 return False 

292 

293 

294def isDEPRECATED(obj): 

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

296 

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

298 C{None} if undetermined. 

299 ''' 

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

301 doc = obj.__doc__.lstrip() 

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

303 except AttributeError: 

304 return None 

305 

306 

307def isfloat(obj, both=False): 

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

309 

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

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

312 

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

314 ''' 

315 try: 

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

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

318 except (TypeError, ValueError): 

319 return False 

320 

321 

322try: 

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

324except AttributeError: # Python 2- 

325 

326 def isidentifier(obj): 

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

328 ''' 

329 return bool(obj and isstr(obj) 

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

331 and not obj[:1].isdigit()) 

332 

333 

334def isinstanceof(obj, *Classes): 

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

336 

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

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

339 

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

341 C{None} otherwise. 

342 ''' 

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

344 

345 

346def isint(obj, both=False): 

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

348 

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

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

351 type and value (C{bool}). 

352 

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

354 or L{Fsum}, C{False} otherwise. 

355 

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

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

358 ''' 

359 if isinstance(obj, _Ints): 

360 return not isbool(obj) 

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

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

363 return obj.is_integer() 

364 except AttributeError: 

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

366 return False 

367 

368 

369def isiterable(obj): 

370 '''Is B{C{obj}}ect C{iterable}? 

371 

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

373 

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

375 ''' 

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

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

378 

379 

380def isiterablen(obj): 

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

382 

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

384 

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

386 ''' 

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

388 

389 

390try: 

391 from keyword import iskeyword # Python 2.7+ 

392except ImportError: 

393 

394 def iskeyword(unused): 

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

396 ''' 

397 return False 

398 

399 

400def isLatLon(obj, ellipsoidal=None): 

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

402 

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

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

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

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

407 

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

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

410 ''' 

411 if ellipsoidal is not None: 

412 try: 

413 return obj.ellipsoidalLatLon if ellipsoidal else obj.sphericalLatLon 

414 except AttributeError: 

415 return None 

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

417 

418 

419def islistuple(obj, minum=0): 

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

421 

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

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

424 

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

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

427 ''' 

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

429 

430 

431def isNvector(obj, ellipsoidal=None): 

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

433 

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

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

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

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

438 

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

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

441 ''' 

442 if ellipsoidal is not None: 

443 try: 

444 return obj.ellipsoidalNvector if ellipsoidal else obj.sphericalNvector 

445 except AttributeError: 

446 return None 

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

448 

449 

450def isodd(x): 

451 '''Is B{C{x}} odd? 

452 

453 @arg x: Value (C{scalar}). 

454 

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

456 ''' 

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

458 

459 

460def isscalar(obj, both=False): 

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

462 

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

464 @kwarg both: If C{True}, check L{Fsum} and L{Fsum2Tuple} 

465 residuals. 

466 

467 @return: C{True} if C{int}, C{float} or C{Fsum/-2Tuple} 

468 with zero residual, C{False} otherwise. 

469 ''' 

470 if isinstance(obj, _Scalars): 

471 return not isbool(obj) # exclude bool 

472 elif both and _MODS.fsums._isFsum_2Tuple(obj): 

473 return bool(obj.residual == 0) 

474 return False 

475 

476 

477def issequence(obj, *excls): 

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

479 

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

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

482 

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

484 

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

486 ''' 

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

488 

489 

490def isstr(obj): 

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

492 

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

494 

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

496 C{False} otherwise. 

497 ''' 

498 return isinstance(obj, _Strs) 

499 

500 

501def issubclassof(Sub, *Supers): 

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

503 

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

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

506 

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

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

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

510 ''' 

511 if isclass(Sub): 

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

513 if t: 

514 return bool(issubclass(Sub, t)) 

515 return None 

516 

517 

518def itemsorted(adict, *items_args, **asorted_reverse): 

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

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

521 

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

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

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

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

526 sorting in C{descending} order. 

527 ''' 

528 def _ins(item): # functools.cmp_to_key 

529 k, v = item 

530 return k.lower() 

531 

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

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

534 

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

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

537 

538 

539def len2(items): 

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

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

542 

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

544 

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

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

547 ''' 

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

549 items = list(items) 

550 return len(items), items 

551 

552 

553def map1(fun1, *xs): # XXX map_ 

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

555 and return a C{tuple} of results. 

556 

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

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

559 

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

561 ''' 

562 return tuple(map(fun1, xs)) 

563 

564 

565def map2(fun, *xs): 

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

567 

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

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

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

571 maintains the Python 2 behavior. 

572 

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

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

575 

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

577 ''' 

578 return tuple(map(fun, *xs)) 

579 

580 

581def neg(x, neg0=None): 

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

583 

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

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

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

587 I{as-is} (C{bool} or C{None}). 

588 

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

590 ''' 

591 return (-x) if x else ( 

592 _0_0 if neg0 is None else ( 

593 x if not neg0 else ( 

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

595 NEG0))) # PYCHOK indent 

596 

597 

598def neg_(*xs): 

599 '''Negate all C{xs} with L{neg}. 

600 

601 @return: A C{map(neg, B{xs})}. 

602 ''' 

603 return map(neg, xs) 

604 

605 

606def _neg0(x): 

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

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

609 ''' 

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

611 

612 

613def _req_d_by(where, **name): 

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

615 ''' 

616 m = _MODS.named 

617 n = m._name__(**name) 

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

619 if n: 

620 m = _DOT_(m, n) 

621 return _SPACE_(_required_, _by_, m) 

622 

623 

624def _reverange(n, stop=-1, step=-1): 

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

626 ''' 

627 return range(n - 1, stop, step) 

628 

629 

630def signBit(x): 

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

632 

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

634 ''' 

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

636 

637 

638def _signOf(x, ref): # in .fsums 

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

640 ''' 

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

642 

643 

644def signOf(x): 

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

646 

647 @return: -1, 0 or +1 (C{int}). 

648 ''' 

649 try: 

650 s = x.signOf() # Fsum instance? 

651 except AttributeError: 

652 s = _signOf(x, 0) 

653 return s 

654 

655 

656def splice(iterable, n=2, **fill): 

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

658 

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

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

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

662 

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

664 M{iterable[i::n] for i=0..n}. 

665 

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

667 

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

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

670 

671 @example: 

672 

673 >>> from pygeodesy import splice 

674 

675 >>> a, b = splice(range(10)) 

676 >>> a, b 

677 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9)) 

678 

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

680 >>> a, b, c 

681 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8)) 

682 

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

684 >>> a, b, c 

685 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1)) 

686 

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

688 ([0, 5], [1, 6], [2, 7], [3, 8], [4]) 

689 

690 >>> splice(range(9), n=1) 

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

692 ''' 

693 if not isint(n): 

694 raise _TypeError(n=n) 

695 

696 t = _xiterablen(iterable) 

697 if not isinstance(t, _list_tuple_types): 

698 t = tuple(t) 

699 

700 if n > 1: 

701 if fill: 

702 fill = _xkwds_get1(fill, fill=MISSING) 

703 if fill is not MISSING: 

704 m = len(t) % n 

705 if m > 0: # same type fill 

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

707 for i in range(n): 

708 # XXX t[i::n] chokes PyChecker 

709 yield t[slice(i, None, n)] 

710 else: 

711 yield t # 1 slice, all 

712 

713 

714def _splituple(strs, *sep_splits): # in .mgrs, .osgr, .webmercator 

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

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

717 ''' 

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

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

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

721 

722 

723def unsigned0(x): 

724 '''Unsign if C{0.0}. 

725 

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

727 ''' 

728 return x if x else _0_0 

729 

730 

731def _xcopy(obj, deep=False): 

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

733 

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

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

736 a shallow copy (C{bool}). 

737 

738 @return: The copy of B{C{obj}}. 

739 ''' 

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

741 

742 

743def _xcoverage(where, *required): 

744 '''(INTERNAL) Import C{coverage} and check required version. 

745 ''' 

746 try: 

747 _xpackage(_xcoverage) 

748 import coverage 

749 except ImportError as x: 

750 raise _xImportError(x, where) 

751 return _xversion(coverage, where, *required) 

752 

753 

754def _xdup(obj, deep=False, **items): 

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

756 

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

758 @kwarg deep: If C{True}, copy deep, otherwise shallow (C{bool}). 

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

760 

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

762 attributes, if any B{C{items}}. 

763 

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

765 ''' 

766 d = _xcopy(obj, deep=deep) 

767 for n, v in items.items(): 

768 if getattr(d, n, v) != v: 

769 setattr(d, n, v) 

770 elif not hasattr(d, n): 

771 t = _MODS.named.classname(obj) 

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

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

774# if items: 

775# _MODS.props._update_all(d) 

776 return d 

777 

778 

779def _xgeographiclib(where, *required): 

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

781 ''' 

782 try: 

783 _xpackage(_xgeographiclib) 

784 import geographiclib 

785 except ImportError as x: 

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

787 return _xversion(geographiclib, where, *required) 

788 

789 

790def _xImportError(exc, where, Error=_ImportError, **name): 

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

792 ''' 

793 t = _req_d_by(where, **name) 

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

795 

796 

797def _xinstanceof(*Types, **names_values): 

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

799 

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

801 positional. 

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

803 with the C{value} to be checked. 

804 

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

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

807 ''' 

808 if not (Types and names_values): 

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

810 

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

812 if not isinstance(v, Types): 

813 raise _TypesError(n, v, *Types) 

814 

815 

816def _xiterable(obj): 

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

818 ''' 

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

820 

821 

822def _xiterablen(obj): 

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

824 ''' 

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

826 

827 

828def _xiterror(obj, _xwhich): 

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

830 ''' 

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

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

833 

834 

835def _xnumpy(where, *required): 

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

837 ''' 

838 try: 

839 _xpackage(_xnumpy) 

840 import numpy 

841 except ImportError as x: 

842 raise _xImportError(x, where) 

843 return _xversion(numpy, where, *required) 

844 

845 

846def _xor(x, *xs): 

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

848 ''' 

849 for x_ in xs: 

850 x ^= x_ 

851 return x 

852 

853 

854def _xpackage(_xpkg): 

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

856 ''' 

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

858 if n in _XPACKAGES: 

859 x = _SPACE_(n, _in_, _PYGEODESY_XPACKAGES_) 

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

861 raise ImportError(_EQUAL_(x, e)) 

862 

863 

864def _xscalar(**names_values): 

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

866 ''' 

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

868 if not isscalar(v): 

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

870 

871 

872def _xscipy(where, *required): 

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

874 ''' 

875 try: 

876 _xpackage(_xscipy) 

877 import scipy 

878 except ImportError as x: 

879 raise _xImportError(x, where) 

880 return _xversion(scipy, where, *required) 

881 

882 

883def _xsubclassof(*Classes, **names_values): 

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

885 

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

887 positional. 

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

889 with the C{value} to be checked. 

890 

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

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

893 ''' 

894 if not (Classes and names_values): 

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

896 

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

898 if not issubclassof(v, *Classes): 

899 raise _TypesError(n, v, *Classes) 

900 

901 

902def _xversion(package, where, *required, **name): 

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

904 ''' 

905 if required: 

906 t = _version_info(package) 

907 if t[:len(required)] < required: 

908 t = _SPACE_(package.__name__, # _dunder_nameof 

909 _version_, _DOT_(*t), 

910 _below_, _DOT_(*required), 

911 _req_d_by(where, **name)) 

912 raise ImportError(t) 

913 return package 

914 

915 

916def _xzip(*args, **strict): # PYCHOK no cover 

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

918 ''' 

919 s = _xkwds_get1(strict, strict=True) 

920 if s: 

921 if _zip is zip: # < (3, 10) 

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

923 raise _NotImplementedError(t, txt=None) 

924 return _zip(*args) 

925 return zip(*args) 

926 

927 

928if _sys_version_info2 < (3, 10): # see .errors 

929 _zip = zip # PYCHOK exported 

930else: # Python 3.10+ 

931 

932 def _zip(*args): 

933 return zip(*args, strict=True) 

934 

935_XPACKAGES = _splituple(_getenv(_PYGEODESY_XPACKAGES_, NN).lower()) 

936 

937# **) MIT License 

938# 

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

940# 

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

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

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

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

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

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

947# 

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

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

950# 

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

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

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

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

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

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

957# OTHER DEALINGS IN THE SOFTWARE.