Coverage for pygeodesy/basics.py: 88%

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 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 

34 

35from copy import copy as _copy, deepcopy as _deepcopy 

36from math import copysign as _copysign 

37# import inspect as _inspect # _MODS 

38 

39__all__ = _ALL_LAZY.basics 

40__version__ = '26.02.22' 

41 

42_below_ = 'below' 

43_list_tuple_types = (list, tuple) 

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 in .internals 

71 _Strs = basestring, str # XXX str == 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 # in .internals 

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 

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 

137 

138 

139def _args_kwds_names(func, splast=False): 

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

141 C{self} for methods. 

142 

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

144 at UNDERscores (C{bool}). 

145 

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) 

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{enumerate}. 

205 ''' 

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

207 yield j, iterable[j] 

208 

209 

210try: 

211 from math import gcd as _gcd 

212except ImportError: # 3.4- 

213 

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 

224 

225 

226def halfs2(str2): 

227 '''Split a string in 2 halfs. 

228 

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

230 

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

232 

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:] 

239 

240 

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 

248 

249 

250def int1s(x): # PYCHOK no cover 

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

252 

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_) 

260 

261 

262def isbool(obj): 

263 '''Is B{C{obj}}ect a C{bool}ean? 

264 

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

266 

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) 

271 

272assert not (isbool(1) or isbool(0) or isbool(None)) # PYCHOK 2 

273 

274 

275def isCartesian(obj, ellipsoidal=None): 

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

277 

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}. 

282 

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) 

292 

293 

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) 

298 

299 

300def iscomplex(obj, both=False): 

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

302 

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

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

305 

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 

313 

314 

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? 

318 

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 

332 

333 

334def isfloat(obj, both=False): 

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

336 

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

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

339 

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 

347 

348 

349try: 

350 isidentifier = str.isidentifier # must be str 

351except AttributeError: # 2.0- 

352 

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()) 

359 

360 

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)) 

366 

367 

368def isinstanceof(obj, *Classes): 

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

370 

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

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

373 

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 

378 

379 

380def isint(obj, both=False): 

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

382 

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}). 

386 

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

388 or L{Fsum}, C{False} otherwise. 

389 

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 

401 

402 

403def isiterable(obj, strict=False): 

404 '''Is B{C{obj}}ect C{iterable}? 

405 

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

407 @kwarg strict: If C{True}, check class attributes (C{bool}). 

408 

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 

413 

414 

415def isiterablen(obj, strict=False): 

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

417 

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

419 @kwarg strict: If C{True}, check class attributes (C{bool}). 

420 

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__')) 

425 

426 

427def isiterabletype(obj, method='__iter__'): 

428 '''Is B{C{obj}}ect an instance of an C{iterable} class or type? 

429 

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

431 @kwarg method: The name of the required method (C{str}). 

432 

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 

445 

446 

447try: 

448 from keyword import iskeyword # 2.7+ 

449except ImportError: 

450 

451 def iskeyword(unused): 

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

453 ''' 

454 return False 

455 

456 

457def isLatLon(obj, ellipsoidal=None): 

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

459 

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}. 

464 

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) 

474 

475 

476def islistuple(obj, minum=0): 

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

478 

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

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

481 

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 

486 

487 

488def isNvector(obj, ellipsoidal=None): 

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

490 

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}. 

495 

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) 

505 

506 

507def isodd(x): 

508 '''Is B{C{x}} odd? 

509 

510 @arg x: Value (C{scalar}). 

511 

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

513 ''' 

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

515 

516 

517def isscalar(obj, both=False): 

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

519 

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

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

522 residuals. 

523 

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 

532 

533 

534def issequence(obj, *excls): 

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

536 

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

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

539 

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

541 

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

543 ''' 

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

545 

546 

547def isstr(obj): 

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

549 

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

551 

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

553 C{False} otherwise. 

554 ''' 

555 return isinstance(obj, _Strs) 

556 

557 

558def issubclassof(Sub, *Supers): 

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

560 

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

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

563 

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 

573 

574 

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. 

578 

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() 

588 

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

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

591 

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

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

594 

595 

596def len2(items): 

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

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

599 

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

601 

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 

608 

609 

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. 

613 

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

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

616 

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

618 ''' 

619 return tuple(map(fun1, xs)) # if len(xs) != 1 else fun1(xs[0]) 

620 

621 

622def map2(fun, *xs, **strict): 

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

624 

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. 

629 

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}). 

634 

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

636 ''' 

637 return tuple(map(fun, *xs, **strict) if strict else map(fun, *xs)) 

638 

639 

640def max2(*xs): 

641 '''Return 2-tuple C{(max(xs), xs.index(max(xs)))}. 

642 ''' 

643 return _max2min2(xs, max, max2) 

644 

645 

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 

659 

660 

661def min2(*xs): 

662 '''Return 2-tuple C{(min(xs), xs.index(min(xs)))}. 

663 ''' 

664 return _max2min2(xs, min, min2) 

665 

666 

667def neg(x, neg0=None): 

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

669 

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}). 

674 

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 

682 

683 

684def neg_(*xs): 

685 '''Negate all C{xs} with L{neg}. 

686 

687 @return: A C{map(neg, B{xs})}. 

688 ''' 

689 return map(neg, xs) 

690 

691 

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 

697 

698 

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) 

708 

709 

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) 

714 

715 

716try: 

717 from math import signbit as signBit # 3.15+ 

718except ImportError: 

719 

720 def signBit(x): 

721 '''Return C{signbit(B{x})}, like C++, see also L{isneg}. 

722 

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

724 ''' 

725 return (x or _copysign(1, x)) < 0 

726 

727 

728def _signOf(x, ref): # in .fsums 

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

730 ''' 

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

732 

733 

734def signOf(x): 

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

736 

737 @return: -1, 0 or +1 (C{int}). 

738 ''' 

739 try: 

740 s = x.signOf() # Fsum instance? 

741 except AttributeError: 

742 s = _signOf(x, 0) 

743 return s 

744 

745 

746def splice(iterable, n=2, **fill): 

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

748 

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

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

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

752 

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

754 M{iterable[i::n] for i=0..n}. 

755 

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

757 

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

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

760 

761 @example: 

762 

763 >>> from pygeodesy import splice 

764 

765 >>> a, b = splice(range(10)) 

766 >>> a, b 

767 ((0, 2, 4, 6, 8), (1, 3, 5, 7, 9)) 

768 

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

770 >>> a, b, c 

771 ((0, 3, 6, 9), (1, 4, 7), (2, 5, 8)) 

772 

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

774 >>> a, b, c 

775 ((0, 3, 6, 9), (1, 4, 7, -1), (2, 5, 8, -1)) 

776 

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

778 ([0, 5], [1, 6], [2, 7], [3, 8], [4]) 

779 

780 >>> splice(range(9), n=1) 

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

782 ''' 

783 if not isint(n): 

784 raise _TypeError(n=n) 

785 

786 t = _xiterablen(iterable) 

787 if not isinstance(t, _list_tuple_types): 

788 t = tuple(t) 

789 

790 if n > 1: 

791 if fill: 

792 fill = _xkwds_get1(fill, fill=MISSING) 

793 if fill is not MISSING: 

794 m = len(t) % n 

795 if m > 0: # same type fill 

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

797 for i in range(n): 

798 # XXX t[i::n] chokes PyChecker 

799 yield t[slice(i, None, n)] 

800 else: 

801 yield t # 1 slice, all 

802 

803 

804def _splituple(strs, *sep_splits): # in .mgrs, ... 

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

806 string into a C{tuple} of stripped C{str}ings. 

807 ''' 

808 if sep_splits: 

809 t = (t.strip() for t in strs.split(*sep_splits)) 

810 else: 

811 t = strs.strip() 

812 if t: 

813 t = t.replace(_COMMA_, _SPACE_).split() 

814 return tuple(t) if t else () 

815 

816 

817def unsigned0(x): 

818 '''Unsign if C{0.0}. 

819 

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

821 ''' 

822 return x if x else _0_0 

823 

824 

825def _xcopy(obj, deep=False): 

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

827 

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

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

830 a shallow copy (C{bool}). 

831 

832 @return: The copy of B{C{obj}}. 

833 ''' 

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

835 

836 

837def _xcoverage(where, *required): # in .__main__ # PYCHOK no cover 

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

839 ''' 

840 try: 

841 _xpackages(_xcoverage) 

842 import coverage 

843 except ImportError as x: 

844 raise _xImportError(x, where) 

845 return _xversion(coverage, where, *required) 

846 

847 

848def _xdup(obj, deep=False, **items): 

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

850 

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

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

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

854 

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

856 attributes, if any B{C{items}}. 

857 

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

859 ''' 

860 d = _xcopy(obj, deep=deep) 

861 for n, v in items.items(): 

862 if getattr(d, n, v) != v: 

863 setattr(d, n, v) 

864 elif not hasattr(d, n): 

865 t = _MODS.named.classname(obj) 

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

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

868# if items: 

869# _MODS.props._update_all(d) 

870 return d 

871 

872 

873def _xgeographiclib(where, *required): 

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

875 ''' 

876 try: 

877 _xpackages(_xgeographiclib) 

878 import geographiclib 

879 except ImportError as x: 

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

881 return _xversion(geographiclib, where, *required) 

882 

883 

884def _xImportError(exc, where, Error=_ImportError, **name): 

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

886 ''' 

887 t = _req_d_by(where, **name) 

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

889 

890 

891def _xinstanceof(*Types, **names_values): 

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

893 

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

895 positional. 

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

897 with the C{value} to be checked. 

898 

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

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

901 ''' 

902 if not (Types and names_values): 

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

904 

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

906 if not isinstance(v, Types): 

907 raise _TypesError(n, v, *Types) 

908 

909 

910def _xiterable(obj): 

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

912 ''' 

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

914 

915 

916def _xiterablen(obj): 

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

918 ''' 

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

920 

921 

922def _xiterror(obj, _xwhich): 

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

924 ''' 

925 t = typename(_xwhich)[2:] # less '_x' 

926 raise _TypeError(repr(obj), txt=_not_(t)) 

927 

928 

929def _xnumpy(where, *required): 

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

931 ''' 

932 try: 

933 _xpackages(_xnumpy) 

934 import numpy 

935 except ImportError as x: 

936 raise _xImportError(x, where) 

937 return _xversion(numpy, where, *required) 

938 

939 

940def _xor(x, *xs): 

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

942 ''' 

943 for x_ in xs: 

944 x ^= x_ 

945 return x 

946 

947 

948def _xpackages(_xhich): 

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

950 ''' 

951 if _XPACKAGES: # PYCHOK no cover 

952 n = typename(_xhich)[2:] # less '_x'