1"""Core implementation of path-based import. 2 3This module is NOT meant to be directly imported! It has been designed such 4that it can be bootstrapped into Python as the implementation of import. As 5such it requires the injection of specific modules and attributes in order to 6work. One should use importlib as the public-facing version of this module. 7 8""" 9# IMPORTANT: Whenever making changes to this module, be sure to run a top-level 10# `make regen-importlib` followed by `make` in order to get the frozen version 11# of the module updated. Not doing so will result in the Makefile to fail for 12# all others who don't have a ./python around to freeze the module in the early 13# stages of compilation. 14# 15 16# See importlib._setup() for what is injected into the global namespace. 17 18# When editing this code be aware that code executed at import time CANNOT 19# reference any injected objects! This includes not only global code but also 20# anything specified at the class level. 21 22# Bootstrap-related code ###################################################### 23_CASE_INSENSITIVE_PLATFORMS_STR_KEY = 'win', 24_CASE_INSENSITIVE_PLATFORMS_BYTES_KEY = 'cygwin', 'darwin' 25_CASE_INSENSITIVE_PLATFORMS = (_CASE_INSENSITIVE_PLATFORMS_BYTES_KEY 26 + _CASE_INSENSITIVE_PLATFORMS_STR_KEY) 27 28 29def _make_relax_case(): 30 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): 31 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS_STR_KEY): 32 key = 'PYTHONCASEOK' 33 else: 34 key = b'PYTHONCASEOK' 35 36 def _relax_case(): 37 """True if filenames must be checked case-insensitively and ignore environment flags are not set.""" 38 return not sys.flags.ignore_environment and key in _os.environ 39 else: 40 def _relax_case(): 41 """True if filenames must be checked case-insensitively.""" 42 return False 43 return _relax_case 44 45 46def _pack_uint32(x): 47 """Convert a 32-bit integer to little-endian.""" 48 return (int(x) & 0xFFFFFFFF).to_bytes(4, 'little') 49 50 51def _unpack_uint32(data): 52 """Convert 4 bytes in little-endian to an integer.""" 53 assert len(data) == 4 54 return int.from_bytes(data, 'little') 55 56def _unpack_uint16(data): 57 """Convert 2 bytes in little-endian to an integer.""" 58 assert len(data) == 2 59 return int.from_bytes(data, 'little') 60 61 62def _path_join(*path_parts): 63 """Replacement for os.path.join().""" 64 return path_sep.join([part.rstrip(path_separators) 65 for part in path_parts if part]) 66 67 68def _path_split(path): 69 """Replacement for os.path.split().""" 70 if len(path_separators) == 1: 71 front, _, tail = path.rpartition(path_sep) 72 return front, tail 73 for x in reversed(path): 74 if x in path_separators: 75 front, tail = path.rsplit(x, maxsplit=1) 76 return front, tail 77 return '', path 78 79 80def _path_stat(path): 81 """Stat the path. 82 83 Made a separate function to make it easier to override in experiments 84 (e.g. cache stat results). 85 86 """ 87 return _os.stat(path) 88 89 90def _path_is_mode_type(path, mode): 91 """Test whether the path is the specified mode type.""" 92 try: 93 stat_info = _path_stat(path) 94 except OSError: 95 return False 96 return (stat_info.st_mode & 0o170000) == mode 97 98 99def _path_isfile(path): 100 """Replacement for os.path.isfile.""" 101 return _path_is_mode_type(path, 0o100000) 102 103 104def _path_isdir(path): 105 """Replacement for os.path.isdir.""" 106 if not path: 107 path = _os.getcwd() 108 return _path_is_mode_type(path, 0o040000) 109 110 111def _path_isabs(path): 112 """Replacement for os.path.isabs. 113 114 Considers a Windows drive-relative path (no drive, but starts with slash) to 115 still be "absolute". 116 """ 117 return path.startswith(path_separators) or path[1:3] in _pathseps_with_colon 118 119 120def _write_atomic(path, data, mode=0o666): 121 """Best-effort function to write data to a path atomically. 122 Be prepared to handle a FileExistsError if concurrent writing of the 123 temporary file is attempted.""" 124 # id() is used to generate a pseudo-random filename. 125 path_tmp = '{}.{}'.format(path, id(path)) 126 fd = _os.open(path_tmp, 127 _os.O_EXCL | _os.O_CREAT | _os.O_WRONLY, mode & 0o666) 128 try: 129 # We first write data to a temporary file, and then use os.replace() to 130 # perform an atomic rename. 131 with _io.FileIO(fd, 'wb') as file: 132 file.write(data) 133 _os.replace(path_tmp, path) 134 except OSError: 135 try: 136 _os.unlink(path_tmp) 137 except OSError: 138 pass 139 raise 140 141 142_code_type = type(_write_atomic.__code__) 143 144 145# Finder/loader utility code ############################################### 146 147# Magic word to reject .pyc files generated by other Python versions. 148# It should change for each incompatible change to the bytecode. 149# 150# The value of CR and LF is incorporated so if you ever read or write 151# a .pyc file in text mode the magic number will be wrong; also, the 152# Apple MPW compiler swaps their values, botching string constants. 153# 154# There were a variety of old schemes for setting the magic number. 155# The current working scheme is to increment the previous value by 156# 10. 157# 158# Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic 159# number also includes a new "magic tag", i.e. a human readable string used 160# to represent the magic number in __pycache__ directories. When you change 161# the magic number, you must also set a new unique magic tag. Generally this 162# can be named after the Python major version of the magic number bump, but 163# it can really be anything, as long as it's different than anything else 164# that's come before. The tags are included in the following table, starting 165# with Python 3.2a0. 166# 167# Known values: 168# Python 1.5: 20121 169# Python 1.5.1: 20121 170# Python 1.5.2: 20121 171# Python 1.6: 50428 172# Python 2.0: 50823 173# Python 2.0.1: 50823 174# Python 2.1: 60202 175# Python 2.1.1: 60202 176# Python 2.1.2: 60202 177# Python 2.2: 60717 178# Python 2.3a0: 62011 179# Python 2.3a0: 62021 180# Python 2.3a0: 62011 (!) 181# Python 2.4a0: 62041 182# Python 2.4a3: 62051 183# Python 2.4b1: 62061 184# Python 2.5a0: 62071 185# Python 2.5a0: 62081 (ast-branch) 186# Python 2.5a0: 62091 (with) 187# Python 2.5a0: 62092 (changed WITH_CLEANUP opcode) 188# Python 2.5b3: 62101 (fix wrong code: for x, in ...) 189# Python 2.5b3: 62111 (fix wrong code: x += yield) 190# Python 2.5c1: 62121 (fix wrong lnotab with for loops and 191# storing constants that should have been removed) 192# Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp) 193# Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode) 194# Python 2.6a1: 62161 (WITH_CLEANUP optimization) 195# Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND) 196# Python 2.7a0: 62181 (optimize conditional branches: 197# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) 198# Python 2.7a0 62191 (introduce SETUP_WITH) 199# Python 2.7a0 62201 (introduce BUILD_SET) 200# Python 2.7a0 62211 (introduce MAP_ADD and SET_ADD) 201# Python 3000: 3000 202# 3010 (removed UNARY_CONVERT) 203# 3020 (added BUILD_SET) 204# 3030 (added keyword-only parameters) 205# 3040 (added signature annotations) 206# 3050 (print becomes a function) 207# 3060 (PEP 3115 metaclass syntax) 208# 3061 (string literals become unicode) 209# 3071 (PEP 3109 raise changes) 210# 3081 (PEP 3137 make __file__ and __name__ unicode) 211# 3091 (kill str8 interning) 212# 3101 (merge from 2.6a0, see 62151) 213# 3103 (__file__ points to source file) 214# Python 3.0a4: 3111 (WITH_CLEANUP optimization). 215# Python 3.0b1: 3131 (lexical exception stacking, including POP_EXCEPT 216 #3021) 217# Python 3.1a1: 3141 (optimize list, set and dict comprehensions: 218# change LIST_APPEND and SET_ADD, add MAP_ADD #2183) 219# Python 3.1a1: 3151 (optimize conditional branches: 220# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE 221 #4715) 222# Python 3.2a1: 3160 (add SETUP_WITH #6101) 223# tag: cpython-32 224# Python 3.2a2: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR #9225) 225# tag: cpython-32 226# Python 3.2a3 3180 (add DELETE_DEREF #4617) 227# Python 3.3a1 3190 (__class__ super closure changed) 228# Python 3.3a1 3200 (PEP 3155 __qualname__ added #13448) 229# Python 3.3a1 3210 (added size modulo 2**32 to the pyc header #13645) 230# Python 3.3a2 3220 (changed PEP 380 implementation #14230) 231# Python 3.3a4 3230 (revert changes to implicit __class__ closure #14857) 232# Python 3.4a1 3250 (evaluate positional default arguments before 233# keyword-only defaults #16967) 234# Python 3.4a1 3260 (add LOAD_CLASSDEREF; allow locals of class to override 235# free vars #17853) 236# Python 3.4a1 3270 (various tweaks to the __class__ closure #12370) 237# Python 3.4a1 3280 (remove implicit class argument) 238# Python 3.4a4 3290 (changes to __qualname__ computation #19301) 239# Python 3.4a4 3300 (more changes to __qualname__ computation #19301) 240# Python 3.4rc2 3310 (alter __qualname__ computation #20625) 241# Python 3.5a1 3320 (PEP 465: Matrix multiplication operator #21176) 242# Python 3.5b1 3330 (PEP 448: Additional Unpacking Generalizations #2292) 243# Python 3.5b2 3340 (fix dictionary display evaluation order #11205) 244# Python 3.5b3 3350 (add GET_YIELD_FROM_ITER opcode #24400) 245# Python 3.5.2 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286) 246# Python 3.6a0 3360 (add FORMAT_VALUE opcode #25483) 247# Python 3.6a1 3361 (lineno delta of code.co_lnotab becomes signed #26107) 248# Python 3.6a2 3370 (16 bit wordcode #26647) 249# Python 3.6a2 3371 (add BUILD_CONST_KEY_MAP opcode #27140) 250# Python 3.6a2 3372 (MAKE_FUNCTION simplification, remove MAKE_CLOSURE 251# #27095) 252# Python 3.6b1 3373 (add BUILD_STRING opcode #27078) 253# Python 3.6b1 3375 (add SETUP_ANNOTATIONS and STORE_ANNOTATION opcodes 254# #27985) 255# Python 3.6b1 3376 (simplify CALL_FUNCTIONs & BUILD_MAP_UNPACK_WITH_CALL 256 #27213) 257# Python 3.6b1 3377 (set __class__ cell from type.__new__ #23722) 258# Python 3.6b2 3378 (add BUILD_TUPLE_UNPACK_WITH_CALL #28257) 259# Python 3.6rc1 3379 (more thorough __class__ validation #23722) 260# Python 3.7a1 3390 (add LOAD_METHOD and CALL_METHOD opcodes #26110) 261# Python 3.7a2 3391 (update GET_AITER #31709) 262# Python 3.7a4 3392 (PEP 552: Deterministic pycs #31650) 263# Python 3.7b1 3393 (remove STORE_ANNOTATION opcode #32550) 264# Python 3.7b5 3394 (restored docstring as the first stmt in the body; 265# this might affected the first line number #32911) 266# Python 3.8a1 3400 (move frame block handling to compiler #17611) 267# Python 3.8a1 3401 (add END_ASYNC_FOR #33041) 268# Python 3.8a1 3410 (PEP570 Python Positional-Only Parameters #36540) 269# Python 3.8b2 3411 (Reverse evaluation order of key: value in dict 270# comprehensions #35224) 271# Python 3.8b2 3412 (Swap the position of positional args and positional 272# only args in ast.arguments #37593) 273# Python 3.8b4 3413 (Fix "break" and "continue" in "finally" #37830) 274# Python 3.9a0 3420 (add LOAD_ASSERTION_ERROR #34880) 275# Python 3.9a0 3421 (simplified bytecode for with blocks #32949) 276# Python 3.9a0 3422 (remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY, POP_FINALLY bytecodes #33387) 277# Python 3.9a2 3423 (add IS_OP, CONTAINS_OP and JUMP_IF_NOT_EXC_MATCH bytecodes #39156) 278# Python 3.9a2 3424 (simplify bytecodes for *value unpacking) 279# Python 3.9a2 3425 (simplify bytecodes for **value unpacking) 280 281# 282# MAGIC must change whenever the bytecode emitted by the compiler may no 283# longer be understood by older implementations of the eval loop (usually 284# due to the addition of new opcodes). 285# 286# Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array 287# in PC/launcher.c must also be updated. 288 289MAGIC_NUMBER = (3425).to_bytes(2, 'little') + b'\r\n' 290_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c 291 292_PYCACHE = '__pycache__' 293_OPT = 'opt-' 294 295SOURCE_SUFFIXES = ['.py'] # _setup() adds .pyw as needed. 296 297BYTECODE_SUFFIXES = ['.pyc'] 298# Deprecated. 299DEBUG_BYTECODE_SUFFIXES = OPTIMIZED_BYTECODE_SUFFIXES = BYTECODE_SUFFIXES 300 301def cache_from_source(path, debug_override=None, *, optimization=None): 302 """Given the path to a .py file, return the path to its .pyc file. 303 304 The .py file does not need to exist; this simply returns the path to the 305 .pyc file calculated as if the .py file were imported. 306 307 The 'optimization' parameter controls the presumed optimization level of 308 the bytecode file. If 'optimization' is not None, the string representation 309 of the argument is taken and verified to be alphanumeric (else ValueError 310 is raised). 311 312 The debug_override parameter is deprecated. If debug_override is not None, 313 a True value is the same as setting 'optimization' to the empty string 314 while a False value is equivalent to setting 'optimization' to '1'. 315 316 If sys.implementation.cache_tag is None then NotImplementedError is raised. 317 318 """ 319 if debug_override is not None: 320 _warnings.warn('the debug_override parameter is deprecated; use ' 321 "'optimization' instead", DeprecationWarning) 322 if optimization is not None: 323 message = 'debug_override or optimization must be set to None' 324 raise TypeError(message) 325 optimization = '' if debug_override else 1 326 path = _os.fspath(path) 327 head, tail = _path_split(path) 328 base, sep, rest = tail.rpartition('.') 329 tag = sys.implementation.cache_tag 330 if tag is None: 331 raise NotImplementedError('sys.implementation.cache_tag is None') 332 almost_filename = ''.join([(base if base else rest), sep, tag]) 333 if optimization is None: 334 if sys.flags.optimize == 0: 335 optimization = '' 336 else: 337 optimization = sys.flags.optimize 338 optimization = str(optimization) 339 if optimization != '': 340 if not optimization.isalnum(): 341 raise ValueError('{!r} is not alphanumeric'.format(optimization)) 342 almost_filename = '{}.{}{}'.format(almost_filename, _OPT, optimization) 343 filename = almost_filename + BYTECODE_SUFFIXES[0] 344 if sys.pycache_prefix is not None: 345 # We need an absolute path to the py file to avoid the possibility of 346 # collisions within sys.pycache_prefix, if someone has two different 347 # `foo/bar.py` on their system and they import both of them using the 348 # same sys.pycache_prefix. Let's say sys.pycache_prefix is 349 # `C:\Bytecode`; the idea here is that if we get `Foo\Bar`, we first 350 # make it absolute (`C:\Somewhere\Foo\Bar`), then make it root-relative 351 # (`Somewhere\Foo\Bar`), so we end up placing the bytecode file in an 352 # unambiguous `C:\Bytecode\Somewhere\Foo\Bar\`. 353 if not _path_isabs(head): 354 head = _path_join(_os.getcwd(), head) 355 356 # Strip initial drive from a Windows path. We know we have an absolute 357 # path here, so the second part of the check rules out a POSIX path that 358 # happens to contain a colon at the second character. 359 if head[1] == ':' and head[0] not in path_separators: 360 head = head[2:] 361 362 # Strip initial path separator from `head` to complete the conversion 363 # back to a root-relative path before joining. 364 return _path_join( 365 sys.pycache_prefix, 366 head.lstrip(path_separators), 367 filename, 368 ) 369 return _path_join(head, _PYCACHE, filename) 370 371 372def source_from_cache(path): 373 """Given the path to a .pyc. file, return the path to its .py file. 374 375 The .pyc file does not need to exist; this simply returns the path to 376 the .py file calculated to correspond to the .pyc file. If path does 377 not conform to PEP 3147/488 format, ValueError will be raised. If 378 sys.implementation.cache_tag is None then NotImplementedError is raised. 379 380 """ 381 if sys.implementation.cache_tag is None: 382 raise NotImplementedError('sys.implementation.cache_tag is None') 383 path = _os.fspath(path) 384 head, pycache_filename = _path_split(path) 385 found_in_pycache_prefix = False 386 if sys.pycache_prefix is not None: 387 stripped_path = sys.pycache_prefix.rstrip(path_separators) 388 if head.startswith(stripped_path + path_sep): 389 head = head[len(stripped_path):] 390 found_in_pycache_prefix = True 391 if not found_in_pycache_prefix: 392 head, pycache = _path_split(head) 393 if pycache != _PYCACHE: 394 raise ValueError(f'{_PYCACHE} not bottom-level directory in ' 395 f'{path!r}') 396 dot_count = pycache_filename.count('.') 397 if dot_count not in {2, 3}: 398 raise ValueError(f'expected only 2 or 3 dots in {pycache_filename!r}') 399 elif dot_count == 3: 400 optimization = pycache_filename.rsplit('.', 2)[-2] 401 if not optimization.startswith(_OPT): 402 raise ValueError("optimization portion of filename does not start " 403 f"with {_OPT!r}") 404 opt_level = optimization[len(_OPT):] 405 if not opt_level.isalnum(): 406 raise ValueError(f"optimization level {optimization!r} is not an " 407 "alphanumeric value") 408 base_filename = pycache_filename.partition('.')[0] 409 return _path_join(head, base_filename + SOURCE_SUFFIXES[0]) 410 411 412def _get_sourcefile(bytecode_path): 413 """Convert a bytecode file path to a source path (if possible). 414 415 This function exists purely for backwards-compatibility for 416 PyImport_ExecCodeModuleWithFilenames() in the C API. 417 418 """ 419 if len(bytecode_path) == 0: 420 return None 421 rest, _, extension = bytecode_path.rpartition('.') 422 if not rest or extension.lower()[-3:-1] != 'py': 423 return bytecode_path 424 try: 425 source_path = source_from_cache(bytecode_path) 426 except (NotImplementedError, ValueError): 427 source_path = bytecode_path[:-1] 428 return source_path if _path_isfile(source_path) else bytecode_path 429 430 431def _get_cached(filename): 432 if filename.endswith(tuple(SOURCE_SUFFIXES)): 433 try: 434 return cache_from_source(filename) 435 except NotImplementedError: 436 pass 437 elif filename.endswith(tuple(BYTECODE_SUFFIXES)): 438 return filename 439 else: 440 return None 441 442 443def _calc_mode(path): 444 """Calculate the mode permissions for a bytecode file.""" 445 try: 446 mode = _path_stat(path).st_mode 447 except OSError: 448 mode = 0o666 449 # We always ensure write access so we can update cached files 450 # later even when the source files are read-only on Windows (#6074) 451 mode |= 0o200 452 return mode 453 454 455def _check_name(method): 456 """Decorator to verify that the module being requested matches the one the 457 loader can handle. 458 459 The first argument (self) must define _name which the second argument is 460 compared against. If the comparison fails then ImportError is raised. 461 462 """ 463 def _check_name_wrapper(self, name=None, *args, **kwargs): 464 if name is None: 465 name = self.name 466 elif self.name != name: 467 raise ImportError('loader for %s cannot handle %s' % 468 (self.name, name), name=name) 469 return method(self, name, *args, **kwargs) 470 try: 471 _wrap = _bootstrap._wrap 472 except NameError: 473 # XXX yuck 474 def _wrap(new, old): 475 for replace in ['__module__', '__name__', '__qualname__', '__doc__']: 476 if hasattr(old, replace): 477 setattr(new, replace, getattr(old, replace)) 478 new.__dict__.update(old.__dict__) 479 _wrap(_check_name_wrapper, method) 480 return _check_name_wrapper 481 482 483def _find_module_shim(self, fullname): 484 """Try to find a loader for the specified module by delegating to 485 self.find_loader(). 486 487 This method is deprecated in favor of finder.find_spec(). 488 489 """ 490 # Call find_loader(). If it returns a string (indicating this 491 # is a namespace package portion), generate a warning and 492 # return None. 493 loader, portions = self.find_loader(fullname) 494 if loader is None and len(portions): 495 msg = 'Not importing directory {}: missing __init__' 496 _warnings.warn(msg.format(portions[0]), ImportWarning) 497 return loader 498 499 500def _classify_pyc(data, name, exc_details): 501 """Perform basic validity checking of a pyc header and return the flags field, 502 which determines how the pyc should be further validated against the source. 503 504 *data* is the contents of the pyc file. (Only the first 16 bytes are 505 required, though.) 506 507 *name* is the name of the module being imported. It is used for logging. 508 509 *exc_details* is a dictionary passed to ImportError if it raised for 510 improved debugging. 511 512 ImportError is raised when the magic number is incorrect or when the flags 513 field is invalid. EOFError is raised when the data is found to be truncated. 514 515 """ 516 magic = data[:4] 517 if magic != MAGIC_NUMBER: 518 message = f'bad magic number in {name!r}: {magic!r}' 519 _bootstrap._verbose_message('{}', message) 520 raise ImportError(message, **exc_details) 521 if len(data) < 16: 522 message = f'reached EOF while reading pyc header of {name!r}' 523 _bootstrap._verbose_message('{}', message) 524 raise EOFError(message) 525 flags = _unpack_uint32(data[4:8]) 526 # Only the first two flags are defined. 527 if flags & ~0b11: 528 message = f'invalid flags {flags!r} in {name!r}' 529 raise ImportError(message, **exc_details) 530 return flags 531 532 533def _validate_timestamp_pyc(data, source_mtime, source_size, name, 534 exc_details): 535 """Validate a pyc against the source last-modified time. 536 537 *data* is the contents of the pyc file. (Only the first 16 bytes are 538 required.) 539 540 *source_mtime* is the last modified timestamp of the source file. 541 542 *source_size* is None or the size of the source file in bytes. 543 544 *name* is the name of the module being imported. It is used for logging. 545 546 *exc_details* is a dictionary passed to ImportError if it raised for 547 improved debugging. 548 549 An ImportError is raised if the bytecode is stale. 550 551 """ 552 if _unpack_uint32(data[8:12]) != (source_mtime & 0xFFFFFFFF): 553 message = f'bytecode is stale for {name!r}' 554 _bootstrap._verbose_message('{}', message) 555 raise ImportError(message, **exc_details) 556 if (source_size is not None and 557 _unpack_uint32(data[12:16]) != (source_size & 0xFFFFFFFF)): 558 raise ImportError(f'bytecode is stale for {name!r}', **exc_details) 559 560 561def _validate_hash_pyc(data, source_hash, name, exc_details): 562 """Validate a hash-based pyc by checking the real source hash against the one in 563 the pyc header. 564 565 *data* is the contents of the pyc file. (Only the first 16 bytes are 566 required.) 567 568 *source_hash* is the importlib.util.source_hash() of the source file. 569 570 *name* is the name of the module being imported. It is used for logging. 571 572 *exc_details* is a dictionary passed to ImportError if it raised for 573 improved debugging. 574 575 An ImportError is raised if the bytecode is stale. 576 577 """ 578 if data[8:16] != source_hash: 579 raise ImportError( 580 f'hash in bytecode doesn\'t match hash of source {name!r}', 581 **exc_details, 582 ) 583 584 585def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None): 586 """Compile bytecode as found in a pyc.""" 587 code = marshal.loads(data) 588 if isinstance(code, _code_type): 589 _bootstrap._verbose_message('code object from {!r}', bytecode_path) 590 if source_path is not None: 591 _imp._fix_co_filename(code, source_path) 592 return code 593 else: 594 raise ImportError('Non-code object in {!r}'.format(bytecode_path), 595 name=name, path=bytecode_path) 596 597 598def _code_to_timestamp_pyc(code, mtime=0, source_size=0): 599 "Produce the data for a timestamp-based pyc." 600 data = bytearray(MAGIC_NUMBER) 601 data.extend(_pack_uint32(0)) 602 data.extend(_pack_uint32(mtime)) 603 data.extend(_pack_uint32(source_size)) 604 data.extend(marshal.dumps(code)) 605 return data 606 607 608def _code_to_hash_pyc(code, source_hash, checked=True): 609 "Produce the data for a hash-based pyc." 610 data = bytearray(MAGIC_NUMBER) 611 flags = 0b1 | checked << 1 612 data.extend(_pack_uint32(flags)) 613 assert len(source_hash) == 8 614 data.extend(source_hash) 615 data.extend(marshal.dumps(code)) 616 return data 617 618 619def decode_source(source_bytes): 620 """Decode bytes representing source code and return the string. 621 622 Universal newline support is used in the decoding. 623 """ 624 import tokenize # To avoid bootstrap issues. 625 source_bytes_readline = _io.BytesIO(source_bytes).readline 626 encoding = tokenize.detect_encoding(source_bytes_readline) 627 newline_decoder = _io.IncrementalNewlineDecoder(None, True) 628 return newline_decoder.decode(source_bytes.decode(encoding[0])) 629 630 631# Module specifications ####################################################### 632 633_POPULATE = object() 634 635 636def spec_from_file_location(name, location=None, *, loader=None, 637 submodule_search_locations=_POPULATE): 638 """Return a module spec based on a file location. 639 640 To indicate that the module is a package, set 641 submodule_search_locations to a list of directory paths. An 642 empty list is sufficient, though its not otherwise useful to the 643 import system. 644 645 The loader must take a spec as its only __init__() arg. 646 647 """ 648 if location is None: 649 # The caller may simply want a partially populated location- 650 # oriented spec. So we set the location to a bogus value and 651 # fill in as much as we can. 652 location = '<unknown>' 653 if hasattr(loader, 'get_filename'): 654 # ExecutionLoader 655 try: 656 location = loader.get_filename(name) 657 except ImportError: 658 pass 659 else: 660 location = _os.fspath(location) 661 662 # If the location is on the filesystem, but doesn't actually exist, 663 # we could return None here, indicating that the location is not 664 # valid. However, we don't have a good way of testing since an 665 # indirect location (e.g. a zip file or URL) will look like a 666 # non-existent file relative to the filesystem. 667 668 spec = _bootstrap.ModuleSpec(name, loader, origin=location) 669 spec._set_fileattr = True 670 671 # Pick a loader if one wasn't provided. 672 if loader is None: 673 for loader_class, suffixes in _get_supported_file_loaders(): 674 if location.endswith(tuple(suffixes)): 675 loader = loader_class(name, location) 676 spec.loader = loader 677 break 678 else: 679 return None 680 681 # Set submodule_search_paths appropriately. 682 if submodule_search_locations is _POPULATE: 683 # Check the loader. 684 if hasattr(loader, 'is_package'): 685 try: 686 is_package = loader.is_package(name) 687 except ImportError: 688 pass 689 else: 690 if is_package: 691 spec.submodule_search_locations = [] 692 else: 693 spec.submodule_search_locations = submodule_search_locations 694 if spec.submodule_search_locations == []: 695 if location: 696 dirname = _path_split(location)[0] 697 spec.submodule_search_locations.append(dirname) 698 699 return spec 700 701 702# Loaders ##################################################################### 703 704class WindowsRegistryFinder: 705 706 """Meta path finder for modules declared in the Windows registry.""" 707 708 REGISTRY_KEY = ( 709 'Software\\Python\\PythonCore\\{sys_version}' 710 '\\Modules\\{fullname}') 711 REGISTRY_KEY_DEBUG = ( 712 'Software\\Python\\PythonCore\\{sys_version}' 713 '\\Modules\\{fullname}\\Debug') 714 DEBUG_BUILD = False # Changed in _setup() 715 716 @classmethod 717 def _open_registry(cls, key): 718 try: 719 return winreg.OpenKey(winreg.HKEY_CURRENT_USER, key) 720 except OSError: 721 return winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, key) 722 723 @classmethod 724 def _search_registry(cls, fullname): 725 if cls.DEBUG_BUILD: 726 registry_key = cls.REGISTRY_KEY_DEBUG 727 else: 728 registry_key = cls.REGISTRY_KEY 729 key = registry_key.format(fullname=fullname, 730 sys_version='%d.%d' % sys.version_info[:2]) 731 try: 732 with cls._open_registry(key) as hkey: 733 filepath = winreg.QueryValue(hkey, '') 734 except OSError: 735 return None 736 return filepath 737 738 @classmethod 739 def find_spec(cls, fullname, path=None, target=None): 740 filepath = cls._search_registry(fullname) 741 if filepath is None: 742 return None 743 try: 744 _path_stat(filepath) 745 except OSError: 746 return None 747 for loader, suffixes in _get_supported_file_loaders(): 748 if filepath.endswith(tuple(suffixes)): 749 spec = _bootstrap.spec_from_loader(fullname, 750 loader(fullname, filepath), 751 origin=filepath) 752 return spec 753 754 @classmethod 755 def find_module(cls, fullname, path=None): 756 """Find module named in the registry. 757 758 This method is deprecated. Use exec_module() instead. 759 760 """ 761 spec = cls.find_spec(fullname, path) 762 if spec is not None: 763 return spec.loader 764 else: 765 return None 766 767 768class _LoaderBasics: 769 770 """Base class of common code needed by both SourceLoader and 771 SourcelessFileLoader.""" 772 773 def is_package(self, fullname): 774 """Concrete implementation of InspectLoader.is_package by checking if 775 the path returned by get_filename has a filename of '__init__.py'.""" 776 filename = _path_split(self.get_filename(fullname))[1] 777 filename_base = filename.rsplit('.', 1)[0] 778 tail_name = fullname.rpartition('.')[2] 779 return filename_base == '__init__' and tail_name != '__init__' 780 781 def create_module(self, spec): 782 """Use default semantics for module creation.""" 783 784 def exec_module(self, module): 785 """Execute the module.""" 786 code = self.get_code(module.__name__) 787 if code is None: 788 raise ImportError('cannot load module {!r} when get_code() ' 789 'returns None'.format(module.__name__)) 790 _bootstrap._call_with_frames_removed(exec, code, module.__dict__) 791 792 def load_module(self, fullname): 793 """This module is deprecated.""" 794 return _bootstrap._load_module_shim(self, fullname) 795 796 797class SourceLoader(_LoaderBasics): 798 799 def path_mtime(self, path): 800 """Optional method that returns the modification time (an int) for the 801 specified path (a str). 802 803 Raises OSError when the path cannot be handled. 804 """ 805 raise OSError 806 807 def path_stats(self, path): 808 """Optional method returning a metadata dict for the specified 809 path (a str). 810 811 Possible keys: 812 - 'mtime' (mandatory) is the numeric timestamp of last source 813 code modification; 814 - 'size' (optional) is the size in bytes of the source code. 815 816 Implementing this method allows the loader to read bytecode files. 817 Raises OSError when the path cannot be handled. 818 """ 819 return {'mtime': self.path_mtime(path)} 820 821 def _cache_bytecode(self, source_path, cache_path, data): 822 """Optional method which writes data (bytes) to a file path (a str). 823 824 Implementing this method allows for the writing of bytecode files. 825 826 The source path is needed in order to correctly transfer permissions 827 """ 828 # For backwards compatibility, we delegate to set_data() 829 return self.set_data(cache_path, data) 830 831 def set_data(self, path, data): 832 """Optional method which writes data (bytes) to a file path (a str). 833 834 Implementing this method allows for the writing of bytecode files. 835 """ 836 837 838 def get_source(self, fullname): 839 """Concrete implementation of InspectLoader.get_source.""" 840 path = self.get_filename(fullname) 841 try: 842 source_bytes = self.get_data(path) 843 except OSError as exc: 844 raise ImportError('source not available through get_data()', 845 name=fullname) from exc 846 return decode_source(source_bytes) 847 848 def source_to_code(self, data, path, *, _optimize=-1): 849 """Return the code object compiled from source. 850 851 The 'data' argument can be any object type that compile() supports. 852 """ 853 return _bootstrap._call_with_frames_removed(compile, data, path, 'exec', 854 dont_inherit=True, optimize=_optimize) 855 856 def get_code(self, fullname): 857 """Concrete implementation of InspectLoader.get_code. 858 859 Reading of bytecode requires path_stats to be implemented. To write 860 bytecode, set_data must also be implemented. 861 862 """ 863 source_path = self.get_filename(fullname) 864 source_mtime = None 865 source_bytes = None 866 source_hash = None 867 hash_based = False 868 check_source = True 869 try: 870 bytecode_path = cache_from_source(source_path) 871 except NotImplementedError: 872 bytecode_path = None 873 else: 874 try: 875 st = self.path_stats(source_path) 876 except OSError: 877 pass 878 else: 879 source_mtime = int(st['mtime']) 880 try: 881 data = self.get_data(bytecode_path) 882 except OSError: 883 pass 884 else: 885 exc_details = { 886 'name': fullname, 887 'path': bytecode_path, 888 } 889 try: 890 flags = _classify_pyc(data, fullname, exc_details) 891 bytes_data = memoryview(data)[16:] 892 hash_based = flags & 0b1 != 0 893 if hash_based: 894 check_source = flags & 0b10 != 0 895 if (_imp.check_hash_based_pycs != 'never' and 896 (check_source or 897 _imp.check_hash_based_pycs == 'always')): 898 source_bytes = self.get_data(source_path) 899 source_hash = _imp.source_hash( 900 _RAW_MAGIC_NUMBER, 901 source_bytes, 902 ) 903 _validate_hash_pyc(data, source_hash, fullname, 904 exc_details) 905 else: 906 _validate_timestamp_pyc( 907 data, 908 source_mtime, 909 st['size'], 910 fullname, 911 exc_details, 912 ) 913 except (ImportError, EOFError): 914 pass 915 else: 916 _bootstrap._verbose_message('{} matches {}', bytecode_path, 917 source_path) 918 return _compile_bytecode(bytes_data, name=fullname, 919 bytecode_path=bytecode_path, 920 source_path=source_path) 921 if source_bytes is None: 922 source_bytes = self.get_data(source_path) 923 code_object = self.source_to_code(source_bytes, source_path) 924 _bootstrap._verbose_message('code object from {}', source_path) 925 if (not sys.dont_write_bytecode and bytecode_path is not None and 926 source_mtime is not None): 927 if hash_based: 928 if source_hash is None: 929 source_hash = _imp.source_hash(source_bytes) 930 data = _code_to_hash_pyc(code_object, source_hash, check_source) 931 else: 932 data = _code_to_timestamp_pyc(code_object, source_mtime, 933 len(source_bytes)) 934 try: 935 self._cache_bytecode(source_path, bytecode_path, data) 936 except NotImplementedError: 937 pass 938 return code_object 939 940 941class FileLoader: 942 943 """Base file loader class which implements the loader protocol methods that 944 require file system usage.""" 945 946 def __init__(self, fullname, path): 947 """Cache the module name and the path to the file found by the 948 finder.""" 949 self.name = fullname 950 self.path = path 951 952 def __eq__(self, other): 953 return (self.__class__ == other.__class__ and 954 self.__dict__ == other.__dict__) 955 956 def __hash__(self): 957 return hash(self.name) ^ hash(self.path) 958 959 @_check_name 960 def load_module(self, fullname): 961 """Load a module from a file. 962 963 This method is deprecated. Use exec_module() instead. 964 965 """ 966 # The only reason for this method is for the name check. 967 # Issue #14857: Avoid the zero-argument form of super so the implementation 968 # of that form can be updated without breaking the frozen module 969 return super(FileLoader, self).load_module(fullname) 970 971 @_check_name 972 def get_filename(self, fullname): 973 """Return the path to the source file as found by the finder.""" 974 return self.path 975 976 def get_data(self, path): 977 """Return the data from path as raw bytes.""" 978 if isinstance(self, (SourceLoader, ExtensionFileLoader)): 979 with _io.open_code(str(path)) as file: 980 return file.read() 981 else: 982 with _io.FileIO(path, 'r') as file: 983 return file.read() 984 985 # ResourceReader ABC API. 986 987 @_check_name 988 def get_resource_reader(self, module): 989 if self.is_package(module): 990 return self 991 return None 992 993 def open_resource(self, resource): 994 path = _path_join(_path_split(self.path)[0], resource) 995 return _io.FileIO(path, 'r') 996 997 def resource_path(self, resource): 998 if not self.is_resource(resource): 999 raise FileNotFoundError 1000 path = _path_join(_path_split(self.path)[0], resource) 1001 return path 1002 1003 def is_resource(self, name): 1004 if path_sep in name: 1005 return False 1006 path = _path_join(_path_split(self.path)[0], name) 1007 return _path_isfile(path) 1008 1009 def contents(self): 1010 return iter(_os.listdir(_path_split(self.path)[0])) 1011 1012 1013class SourceFileLoader(FileLoader, SourceLoader): 1014 1015 """Concrete implementation of SourceLoader using the file system.""" 1016 1017 def path_stats(self, path): 1018 """Return the metadata for the path.""" 1019 st = _path_stat(path) 1020 return {'mtime': st.st_mtime, 'size': st.st_size} 1021 1022 def _cache_bytecode(self, source_path, bytecode_path, data): 1023 # Adapt between the two APIs 1024 mode = _calc_mode(source_path) 1025 return self.set_data(bytecode_path, data, _mode=mode) 1026 1027 def set_data(self, path, data, *, _mode=0o666): 1028 """Write bytes data to a file.""" 1029 parent, filename = _path_split(path) 1030 path_parts = [] 1031 # Figure out what directories are missing. 1032 while parent and not _path_isdir(parent): 1033 parent, part = _path_split(parent) 1034 path_parts.append(part) 1035 # Create needed directories. 1036 for part in reversed(path_parts): 1037 parent = _path_join(parent, part) 1038 try: 1039 _os.mkdir(parent) 1040 except FileExistsError: 1041 # Probably another Python process already created the dir. 1042 continue 1043 except OSError as exc: 1044 # Could be a permission error, read-only filesystem: just forget 1045 # about writing the data. 1046 _bootstrap._verbose_message('could not create {!r}: {!r}', 1047 parent, exc) 1048 return 1049 try: 1050 _write_atomic(path, data, _mode) 1051 _bootstrap._verbose_message('created {!r}', path) 1052 except OSError as exc: 1053 # Same as above: just don't write the bytecode. 1054 _bootstrap._verbose_message('could not create {!r}: {!r}', path, 1055 exc) 1056 1057 1058class SourcelessFileLoader(FileLoader, _LoaderBasics): 1059 1060 """Loader which handles sourceless file imports.""" 1061 1062 def get_code(self, fullname): 1063 path = self.get_filename(fullname) 1064 data = self.get_data(path) 1065 # Call _classify_pyc to do basic validation of the pyc but ignore the 1066 # result. There's no source to check against. 1067 exc_details = { 1068 'name': fullname, 1069 'path': path, 1070 } 1071 _classify_pyc(data, fullname, exc_details) 1072 return _compile_bytecode( 1073 memoryview(data)[16:], 1074 name=fullname, 1075 bytecode_path=path, 1076 ) 1077 1078 def get_source(self, fullname): 1079 """Return None as there is no source code.""" 1080 return None 1081 1082 1083# Filled in by _setup(). 1084EXTENSION_SUFFIXES = [] 1085 1086 1087class ExtensionFileLoader(FileLoader, _LoaderBasics): 1088 1089 """Loader for extension modules. 1090 1091 The constructor is designed to work with FileFinder. 1092 1093 """ 1094 1095 def __init__(self, name, path): 1096 self.name = name 1097 self.path = path 1098 1099 def __eq__(self, other): 1100 return (self.__class__ == other.__class__ and 1101 self.__dict__ == other.__dict__) 1102 1103 def __hash__(self): 1104 return hash(self.name) ^ hash(self.path) 1105 1106 def create_module(self, spec): 1107 """Create an unitialized extension module""" 1108 module = _bootstrap._call_with_frames_removed( 1109 _imp.create_dynamic, spec) 1110 _bootstrap._verbose_message('extension module {!r} loaded from {!r}', 1111 spec.name, self.path) 1112 return module 1113 1114 def exec_module(self, module): 1115 """Initialize an extension module""" 1116 _bootstrap._call_with_frames_removed(_imp.exec_dynamic, module) 1117 _bootstrap._verbose_message('extension module {!r} executed from {!r}', 1118 self.name, self.path) 1119 1120 def is_package(self, fullname): 1121 """Return True if the extension module is a package.""" 1122 file_name = _path_split(self.path)[1] 1123 return any(file_name == '__init__' + suffix 1124 for suffix in EXTENSION_SUFFIXES) 1125 1126 def get_code(self, fullname): 1127 """Return None as an extension module cannot create a code object.""" 1128 return None 1129 1130 def get_source(self, fullname): 1131 """Return None as extension modules have no source code.""" 1132 return None 1133 1134 @_check_name 1135 def get_filename(self, fullname): 1136 """Return the path to the source file as found by the finder.""" 1137 return self.path 1138 1139 1140class _NamespacePath: 1141 """Represents a namespace package's path. It uses the module name 1142 to find its parent module, and from there it looks up the parent's 1143 __path__. When this changes, the module's own path is recomputed, 1144 using path_finder. For top-level modules, the parent module's path 1145 is sys.path.""" 1146 1147 def __init__(self, name, path, path_finder): 1148 self._name = name 1149 self._path = path 1150 self._last_parent_path = tuple(self._get_parent_path()) 1151 self._path_finder = path_finder 1152 1153 def _find_parent_path_names(self): 1154 """Returns a tuple of (parent-module-name, parent-path-attr-name)""" 1155 parent, dot, me = self._name.rpartition('.') 1156 if dot == '': 1157 # This is a top-level module. sys.path contains the parent path. 1158 return 'sys', 'path' 1159 # Not a top-level module. parent-module.__path__ contains the 1160 # parent path. 1161 return parent, '__path__' 1162 1163 def _get_parent_path(self): 1164 parent_module_name, path_attr_name = self._find_parent_path_names() 1165 return getattr(sys.modules[parent_module_name], path_attr_name) 1166 1167 def _recalculate(self): 1168 # If the parent's path has changed, recalculate _path 1169 parent_path = tuple(self._get_parent_path()) # Make a copy 1170 if parent_path != self._last_parent_path: 1171 spec = self._path_finder(self._name, parent_path) 1172 # Note that no changes are made if a loader is returned, but we 1173 # do remember the new parent path 1174 if spec is not None and spec.loader is None: 1175 if spec.submodule_search_locations: 1176 self._path = spec.submodule_search_locations 1177 self._last_parent_path = parent_path # Save the copy 1178 return self._path 1179 1180 def __iter__(self): 1181 return iter(self._recalculate()) 1182 1183 def __getitem__(self, index): 1184 return self._recalculate()[index] 1185 1186 def __setitem__(self, index, path): 1187 self._path[index] = path 1188 1189 def __len__(self): 1190 return len(self._recalculate()) 1191 1192 def __repr__(self): 1193 return '_NamespacePath({!r})'.format(self._path) 1194 1195 def __contains__(self, item): 1196 return item in self._recalculate() 1197 1198 def append(self, item): 1199 self._path.append(item) 1200 1201 1202# We use this exclusively in module_from_spec() for backward-compatibility. 1203class _NamespaceLoader: 1204 def __init__(self, name, path, path_finder): 1205 self._path = _NamespacePath(name, path, path_finder) 1206 1207 @classmethod 1208 def module_repr(cls, module): 1209 """Return repr for the module. 1210 1211 The method is deprecated. The import machinery does the job itself. 1212 1213 """ 1214 return '<module {!r} (namespace)>'.format(module.__name__) 1215 1216 def is_package(self, fullname): 1217 return True 1218 1219 def get_source(self, fullname): 1220 return '' 1221 1222 def get_code(self, fullname): 1223 return compile('', '<string>', 'exec', dont_inherit=True) 1224 1225 def create_module(self, spec): 1226 """Use default semantics for module creation.""" 1227 1228 def exec_module(self, module): 1229 pass 1230 1231 def load_module(self, fullname): 1232 """Load a namespace module. 1233 1234 This method is deprecated. Use exec_module() instead. 1235 1236 """ 1237 # The import system never calls this method. 1238 _bootstrap._verbose_message('namespace module loaded with path {!r}', 1239 self._path) 1240 return _bootstrap._load_module_shim(self, fullname) 1241 1242 1243# Finders ##################################################################### 1244 1245class PathFinder: 1246 1247 """Meta path finder for sys.path and package __path__ attributes.""" 1248 1249 @classmethod 1250 def invalidate_caches(cls): 1251 """Call the invalidate_caches() method on all path entry finders 1252 stored in sys.path_importer_caches (where implemented).""" 1253 for name, finder in list(sys.path_importer_cache.items()): 1254 if finder is None: 1255 del sys.path_importer_cache[name] 1256 elif hasattr(finder, 'invalidate_caches'): 1257 finder.invalidate_caches() 1258 1259 @classmethod 1260 def _path_hooks(cls, path): 1261 """Search sys.path_hooks for a finder for 'path'.""" 1262 if sys.path_hooks is not None and not sys.path_hooks: 1263 _warnings.warn('sys.path_hooks is empty', ImportWarning) 1264 for hook in sys.path_hooks: 1265 try: 1266 return hook(path) 1267 except ImportError: 1268 continue 1269 else: 1270 return None 1271 1272 @classmethod 1273 def _path_importer_cache(cls, path): 1274 """Get the finder for the path entry from sys.path_importer_cache. 1275 1276 If the path entry is not in the cache, find the appropriate finder 1277 and cache it. If no finder is available, store None. 1278 1279 """ 1280 if path == '': 1281 try: 1282 path = _os.getcwd() 1283 except FileNotFoundError: 1284 # Don't cache the failure as the cwd can easily change to 1285 # a valid directory later on. 1286 return None 1287 try: 1288 finder = sys.path_importer_cache[path] 1289 except KeyError: 1290 finder = cls._path_hooks(path) 1291 sys.path_importer_cache[path] = finder 1292 return finder 1293 1294 @classmethod 1295 def _legacy_get_spec(cls, fullname, finder): 1296 # This would be a good place for a DeprecationWarning if 1297 # we ended up going that route. 1298 if hasattr(finder, 'find_loader'): 1299 loader, portions = finder.find_loader(fullname) 1300 else: 1301 loader = finder.find_module(fullname) 1302 portions = [] 1303 if loader is not None: 1304 return _bootstrap.spec_from_loader(fullname, loader) 1305 spec = _bootstrap.ModuleSpec(fullname, None) 1306 spec.submodule_search_locations = portions 1307 return spec 1308 1309 @classmethod 1310 def _get_spec(cls, fullname, path, target=None): 1311 """Find the loader or namespace_path for this module/package name.""" 1312 # If this ends up being a namespace package, namespace_path is 1313 # the list of paths that will become its __path__ 1314 namespace_path = [] 1315 for entry in path: 1316 if not isinstance(entry, (str, bytes)): 1317 continue 1318 finder = cls._path_importer_cache(entry) 1319 if finder is not None: 1320 if hasattr(finder, 'find_spec'): 1321 spec = finder.find_spec(fullname, target) 1322 else: 1323 spec = cls._legacy_get_spec(fullname, finder) 1324 if spec is None: 1325 continue 1326 if spec.loader is not None: 1327 return spec 1328 portions = spec.submodule_search_locations 1329 if portions is None: 1330 raise ImportError('spec missing loader') 1331 # This is possibly part of a namespace package. 1332 # Remember these path entries (if any) for when we 1333 # create a namespace package, and continue iterating 1334 # on path. 1335 namespace_path.extend(portions) 1336 else: 1337 spec = _bootstrap.ModuleSpec(fullname, None) 1338 spec.submodule_search_locations = namespace_path 1339 return spec 1340 1341 @classmethod 1342 def find_spec(cls, fullname, path=None, target=None): 1343 """Try to find a spec for 'fullname' on sys.path or 'path'. 1344 1345 The search is based on sys.path_hooks and sys.path_importer_cache. 1346 """ 1347 if path is None: 1348 path = sys.path 1349 spec = cls._get_spec(fullname, path, target) 1350 if spec is None: 1351 return None 1352 elif spec.loader is None: 1353 namespace_path = spec.submodule_search_locations 1354 if namespace_path: 1355 # We found at least one namespace path. Return a spec which 1356 # can create the namespace package. 1357 spec.origin = None 1358 spec.submodule_search_locations = _NamespacePath(fullname, namespace_path, cls._get_spec) 1359 return spec 1360 else: 1361 return None 1362 else: 1363 return spec 1364 1365 @classmethod 1366 def find_module(cls, fullname, path=None): 1367 """find the module on sys.path or 'path' based on sys.path_hooks and 1368 sys.path_importer_cache. 1369 1370 This method is deprecated. Use find_spec() instead. 1371 1372 """ 1373 spec = cls.find_spec(fullname, path) 1374 if spec is None: 1375 return None 1376 return spec.loader 1377 1378 @classmethod 1379 def find_distributions(cls, *args, **kwargs): 1380 """ 1381 Find distributions. 1382 1383 Return an iterable of all Distribution instances capable of 1384 loading the metadata for packages matching ``context.name`` 1385 (or all names if ``None`` indicated) along the paths in the list 1386 of directories ``context.path``. 1387 """ 1388 from importlib.metadata import MetadataPathFinder 1389 return MetadataPathFinder.find_distributions(*args, **kwargs) 1390 1391 1392class FileFinder: 1393 1394 """File-based finder. 1395 1396 Interactions with the file system are cached for performance, being 1397 refreshed when the directory the finder is handling has been modified. 1398 1399 """ 1400 1401 def __init__(self, path, *loader_details): 1402 """Initialize with the path to search on and a variable number of 1403 2-tuples containing the loader and the file suffixes the loader 1404 recognizes.""" 1405 loaders = [] 1406 for loader, suffixes in loader_details: 1407 loaders.extend((suffix, loader) for suffix in suffixes) 1408 self._loaders = loaders 1409 # Base (directory) path 1410 self.path = path or '.' 1411 self._path_mtime = -1 1412 self._path_cache = set() 1413 self._relaxed_path_cache = set() 1414 1415 def invalidate_caches(self): 1416 """Invalidate the directory mtime.""" 1417 self._path_mtime = -1 1418 1419 find_module = _find_module_shim 1420 1421 def find_loader(self, fullname): 1422 """Try to find a loader for the specified module, or the namespace 1423 package portions. Returns (loader, list-of-portions). 1424 1425 This method is deprecated. Use find_spec() instead. 1426 1427 """ 1428 spec = self.find_spec(fullname) 1429 if spec is None: 1430 return None, [] 1431 return spec.loader, spec.submodule_search_locations or [] 1432 1433 def _get_spec(self, loader_class, fullname, path, smsl, target): 1434 loader = loader_class(fullname, path) 1435 return spec_from_file_location(fullname, path, loader=loader, 1436 submodule_search_locations=smsl) 1437 1438 def find_spec(self, fullname, target=None): 1439 """Try to find a spec for the specified module. 1440 1441 Returns the matching spec, or None if not found. 1442 """ 1443 is_namespace = False 1444 tail_module = fullname.rpartition('.')[2] 1445 try: 1446 mtime = _path_stat(self.path or _os.getcwd()).st_mtime 1447 except OSError: 1448 mtime = -1 1449 if mtime != self._path_mtime: 1450 self._fill_cache() 1451 self._path_mtime = mtime 1452 # tail_module keeps the original casing, for __file__ and friends 1453 if _relax_case(): 1454 cache = self._relaxed_path_cache 1455 cache_module = tail_module.lower() 1456 else: 1457 cache = self._path_cache 1458 cache_module = tail_module 1459 # Check if the module is the name of a directory (and thus a package). 1460 if cache_module in cache: 1461 base_path = _path_join(self.path, tail_module) 1462 for suffix, loader_class in self._loaders: 1463 init_filename = '__init__' + suffix 1464 full_path = _path_join(base_path, init_filename) 1465 if _path_isfile(full_path): 1466 return self._get_spec(loader_class, fullname, full_path, [base_path], target) 1467 else: 1468 # If a namespace package, return the path if we don't 1469 # find a module in the next section. 1470 is_namespace = _path_isdir(base_path) 1471 # Check for a file w/ a proper suffix exists. 1472 for suffix, loader_class in self._loaders: 1473 full_path = _path_join(self.path, tail_module + suffix) 1474 _bootstrap._verbose_message('trying {}', full_path, verbosity=2) 1475 if cache_module + suffix in cache: 1476 if _path_isfile(full_path): 1477 return self._get_spec(loader_class, fullname, full_path, 1478 None, target) 1479 if is_namespace: 1480 _bootstrap._verbose_message('possible namespace for {}', base_path) 1481 spec = _bootstrap.ModuleSpec(fullname, None) 1482 spec.submodule_search_locations = [base_path] 1483 return spec 1484 return None 1485 1486 def _fill_cache(self): 1487 """Fill the cache of potential modules and packages for this directory.""" 1488 path = self.path 1489 try: 1490 contents = _os.listdir(path or _os.getcwd()) 1491 except (FileNotFoundError, PermissionError, NotADirectoryError): 1492 # Directory has either been removed, turned into a file, or made 1493 # unreadable. 1494 contents = [] 1495 # We store two cached versions, to handle runtime changes of the 1496 # PYTHONCASEOK environment variable. 1497 if not sys.platform.startswith('win'): 1498 self._path_cache = set(contents) 1499 else: 1500 # Windows users can import modules with case-insensitive file 1501 # suffixes (for legacy reasons). Make the suffix lowercase here 1502 # so it's done once instead of for every import. This is safe as 1503 # the specified suffixes to check against are always specified in a 1504 # case-sensitive manner. 1505 lower_suffix_contents = set() 1506 for item in contents: 1507 name, dot, suffix = item.partition('.') 1508 if dot: 1509 new_name = '{}.{}'.format(name, suffix.lower()) 1510 else: 1511 new_name = name 1512 lower_suffix_contents.add(new_name) 1513 self._path_cache = lower_suffix_contents 1514 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): 1515 self._relaxed_path_cache = {fn.lower() for fn in contents} 1516 1517 @classmethod 1518 def path_hook(cls, *loader_details): 1519 """A class method which returns a closure to use on sys.path_hook 1520 which will return an instance using the specified loaders and the path 1521 called on the closure. 1522 1523 If the path called on the closure is not a directory, ImportError is 1524 raised. 1525 1526 """ 1527 def path_hook_for_FileFinder(path): 1528 """Path hook for importlib.machinery.FileFinder.""" 1529 if not _path_isdir(path): 1530 raise ImportError('only directories are supported', path=path) 1531 return cls(path, *loader_details) 1532 1533 return path_hook_for_FileFinder 1534 1535 def __repr__(self): 1536 return 'FileFinder({!r})'.format(self.path) 1537 1538 1539# Import setup ############################################################### 1540 1541def _fix_up_module(ns, name, pathname, cpathname=None): 1542 # This function is used by PyImport_ExecCodeModuleObject(). 1543 loader = ns.get('__loader__') 1544 spec = ns.get('__spec__') 1545 if not loader: 1546 if spec: 1547 loader = spec.loader 1548 elif pathname == cpathname: 1549 loader = SourcelessFileLoader(name, pathname) 1550 else: 1551 loader = SourceFileLoader(name, pathname) 1552 if not spec: 1553 spec = spec_from_file_location(name, pathname, loader=loader) 1554 try: 1555 ns['__spec__'] = spec 1556 ns['__loader__'] = loader 1557 ns['__file__'] = pathname 1558 ns['__cached__'] = cpathname 1559 except Exception: 1560 # Not important enough to report. 1561 pass 1562 1563 1564def _get_supported_file_loaders(): 1565 """Returns a list of file-based module loaders. 1566 1567 Each item is a tuple (loader, suffixes). 1568 """ 1569 extensions = ExtensionFileLoader, _imp.extension_suffixes() 1570 source = SourceFileLoader, SOURCE_SUFFIXES 1571 bytecode = SourcelessFileLoader, BYTECODE_SUFFIXES 1572 return [extensions, source, bytecode] 1573 1574 1575def _setup(_bootstrap_module): 1576 """Setup the path-based importers for importlib by importing needed 1577 built-in modules and injecting them into the global namespace. 1578 1579 Other components are extracted from the core bootstrap module. 1580 1581 """ 1582 global sys, _imp, _bootstrap 1583 _bootstrap = _bootstrap_module 1584 sys = _bootstrap.sys 1585 _imp = _bootstrap._imp 1586 1587 self_module = sys.modules[__name__] 1588 1589 # Directly load the os module (needed during bootstrap). 1590 os_details = ('posix', ['/']), ('nt', ['\\', '/']) 1591 for builtin_os, path_separators in os_details: 1592 # Assumption made in _path_join() 1593 assert all(len(sep) == 1 for sep in path_separators) 1594 path_sep = path_separators[0] 1595 if builtin_os in sys.modules: 1596 os_module = sys.modules[builtin_os] 1597 break 1598 else: 1599 try: 1600 os_module = _bootstrap._builtin_from_name(builtin_os) 1601 break 1602 except ImportError: 1603 continue 1604 else: 1605 raise ImportError('importlib requires posix or nt') 1606 1607 setattr(self_module, '_os', os_module) 1608 setattr(self_module, 'path_sep', path_sep) 1609 setattr(self_module, 'path_separators', ''.join(path_separators)) 1610 setattr(self_module, '_pathseps_with_colon', {f':{s}' for s in path_separators}) 1611 1612 # Directly load built-in modules needed during bootstrap. 1613 builtin_names = ['_io', '_warnings', 'marshal'] 1614 if builtin_os == 'nt': 1615 builtin_names.append('winreg') 1616 for builtin_name in builtin_names: 1617 if builtin_name not in sys.modules: 1618 builtin_module = _bootstrap._builtin_from_name(builtin_name) 1619 else: 1620 builtin_module = sys.modules[builtin_name] 1621 setattr(self_module, builtin_name, builtin_module) 1622 1623 # Constants 1624 setattr(self_module, '_relax_case', _make_relax_case()) 1625 EXTENSION_SUFFIXES.extend(_imp.extension_suffixes()) 1626 if builtin_os == 'nt': 1627 SOURCE_SUFFIXES.append('.pyw') 1628 if '_d.pyd' in EXTENSION_SUFFIXES: 1629 WindowsRegistryFinder.DEBUG_BUILD = True 1630 1631 1632def _install(_bootstrap_module): 1633 """Install the path-based import components.""" 1634 _setup(_bootstrap_module) 1635 supported_loaders = _get_supported_file_loaders() 1636 sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders)]) 1637 sys.meta_path.append(PathFinder) 1638