1 """Core implementation of path-based import. 2 3 This module is NOT meant to be directly imported! It has been designed such 4 that it can be bootstrapped into Python as the implementation of import. As 5 such it requires the injection of specific modules and attributes in order to 6 work. One should use importlib as the public-facing version of this module. 7 8 """ 9 # 10 # IMPORTANT: Whenever making changes to this module, be sure to run 11 # a top-level make in order to get the frozen version of the module 12 # updated. Not doing so will result in the Makefile to fail for 13 # all others who don't have a ./python around to freeze the module 14 # in the early stages of compilation. 15 # 16 17 # See importlib._setup() for what is injected into the global namespace. 18 19 # When editing this code be aware that code executed at import time CANNOT 20 # reference any injected objects! This includes not only global code but also 21 # anything specified at the class level. 22 23 # Bootstrap-related code ###################################################### 24 _CASE_INSENSITIVE_PLATFORMS_STR_KEY = 'win', 25 _CASE_INSENSITIVE_PLATFORMS_BYTES_KEY = 'cygwin', 'darwin' 26 _CASE_INSENSITIVE_PLATFORMS = (_CASE_INSENSITIVE_PLATFORMS_BYTES_KEY 27 + _CASE_INSENSITIVE_PLATFORMS_STR_KEY) 28 29 30 def _make_relax_case(): 31 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): 32 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS_STR_KEY): 33 key = 'PYTHONCASEOK' 34 else: 35 key = b'PYTHONCASEOK' 36 37 def _relax_case(): 38 """True if filenames must be checked case-insensitively.""" 39 return key in _os.environ 40 else: 41 def _relax_case(): 42 """True if filenames must be checked case-insensitively.""" 43 return False 44 return _relax_case 45 46 47 def _w_long(x): 48 """Convert a 32-bit integer to little-endian.""" 49 return (int(x) & 0xFFFFFFFF).to_bytes(4, 'little') 50 51 52 def _r_long(int_bytes): 53 """Convert 4 bytes in little-endian to an integer.""" 54 return int.from_bytes(int_bytes, 'little') 55 56 57 def _path_join(*path_parts): 58 """Replacement for os.path.join().""" 59 return path_sep.join([part.rstrip(path_separators) 60 for part in path_parts if part]) 61 62 63 def _path_split(path): 64 """Replacement for os.path.split().""" 65 if len(path_separators) == 1: 66 front, _, tail = path.rpartition(path_sep) 67 return front, tail 68 for x in reversed(path): 69 if x in path_separators: 70 front, tail = path.rsplit(x, maxsplit=1) 71 return front, tail 72 return '', path 73 74 75 def _path_stat(path): 76 """Stat the path. 77 78 Made a separate function to make it easier to override in experiments 79 (e.g. cache stat results). 80 81 """ 82 return _os.stat(path) 83 84 85 def _path_is_mode_type(path, mode): 86 """Test whether the path is the specified mode type.""" 87 try: 88 stat_info = _path_stat(path) 89 except OSError: 90 return False 91 return (stat_info.st_mode & 0o170000) == mode 92 93 94 def _path_isfile(path): 95 """Replacement for os.path.isfile.""" 96 return _path_is_mode_type(path, 0o100000) 97 98 99 def _path_isdir(path): 100 """Replacement for os.path.isdir.""" 101 if not path: 102 path = _os.getcwd() 103 return _path_is_mode_type(path, 0o040000) 104 105 106 def _write_atomic(path, data, mode=0o666): 107 """Best-effort function to write data to a path atomically. 108 Be prepared to handle a FileExistsError if concurrent writing of the 109 temporary file is attempted.""" 110 # id() is used to generate a pseudo-random filename. 111 path_tmp = '{}.{}'.format(path, id(path)) 112 fd = _os.open(path_tmp, 113 _os.O_EXCL | _os.O_CREAT | _os.O_WRONLY, mode & 0o666) 114 try: 115 # We first write data to a temporary file, and then use os.replace() to 116 # perform an atomic rename. 117 with _io.FileIO(fd, 'wb') as file: 118 file.write(data) 119 _os.replace(path_tmp, path) 120 except OSError: 121 try: 122 _os.unlink(path_tmp) 123 except OSError: 124 pass 125 raise 126 127 128 _code_type = type(_write_atomic.__code__) 129 130 131 # Finder/loader utility code ############################################### 132 133 # Magic word to reject .pyc files generated by other Python versions. 134 # It should change for each incompatible change to the bytecode. 135 # 136 # The value of CR and LF is incorporated so if you ever read or write 137 # a .pyc file in text mode the magic number will be wrong; also, the 138 # Apple MPW compiler swaps their values, botching string constants. 139 # 140 # There were a variety of old schemes for setting the magic number. 141 # The current working scheme is to increment the previous value by 142 # 10. 143 # 144 # Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic 145 # number also includes a new "magic tag", i.e. a human readable string used 146 # to represent the magic number in __pycache__ directories. When you change 147 # the magic number, you must also set a new unique magic tag. Generally this 148 # can be named after the Python major version of the magic number bump, but 149 # it can really be anything, as long as it's different than anything else 150 # that's come before. The tags are included in the following table, starting 151 # with Python 3.2a0. 152 # 153 # Known values: 154 # Python 1.5: 20121 155 # Python 1.5.1: 20121 156 # Python 1.5.2: 20121 157 # Python 1.6: 50428 158 # Python 2.0: 50823 159 # Python 2.0.1: 50823 160 # Python 2.1: 60202 161 # Python 2.1.1: 60202 162 # Python 2.1.2: 60202 163 # Python 2.2: 60717 164 # Python 2.3a0: 62011 165 # Python 2.3a0: 62021 166 # Python 2.3a0: 62011 (!) 167 # Python 2.4a0: 62041 168 # Python 2.4a3: 62051 169 # Python 2.4b1: 62061 170 # Python 2.5a0: 62071 171 # Python 2.5a0: 62081 (ast-branch) 172 # Python 2.5a0: 62091 (with) 173 # Python 2.5a0: 62092 (changed WITH_CLEANUP opcode) 174 # Python 2.5b3: 62101 (fix wrong code: for x, in ...) 175 # Python 2.5b3: 62111 (fix wrong code: x += yield) 176 # Python 2.5c1: 62121 (fix wrong lnotab with for loops and 177 # storing constants that should have been removed) 178 # Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp) 179 # Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode) 180 # Python 2.6a1: 62161 (WITH_CLEANUP optimization) 181 # Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND) 182 # Python 2.7a0: 62181 (optimize conditional branches: 183 # introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) 184 # Python 2.7a0 62191 (introduce SETUP_WITH) 185 # Python 2.7a0 62201 (introduce BUILD_SET) 186 # Python 2.7a0 62211 (introduce MAP_ADD and SET_ADD) 187 # Python 3000: 3000 188 # 3010 (removed UNARY_CONVERT) 189 # 3020 (added BUILD_SET) 190 # 3030 (added keyword-only parameters) 191 # 3040 (added signature annotations) 192 # 3050 (print becomes a function) 193 # 3060 (PEP 3115 metaclass syntax) 194 # 3061 (string literals become unicode) 195 # 3071 (PEP 3109 raise changes) 196 # 3081 (PEP 3137 make __file__ and __name__ unicode) 197 # 3091 (kill str8 interning) 198 # 3101 (merge from 2.6a0, see 62151) 199 # 3103 (__file__ points to source file) 200 # Python 3.0a4: 3111 (WITH_CLEANUP optimization). 201 # Python 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT) 202 # Python 3.1a0: 3141 (optimize list, set and dict comprehensions: 203 # change LIST_APPEND and SET_ADD, add MAP_ADD) 204 # Python 3.1a0: 3151 (optimize conditional branches: 205 # introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) 206 # Python 3.2a0: 3160 (add SETUP_WITH) 207 # tag: cpython-32 208 # Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR) 209 # tag: cpython-32 210 # Python 3.2a2 3180 (add DELETE_DEREF) 211 # Python 3.3a0 3190 __class__ super closure changed 212 # Python 3.3a0 3200 (__qualname__ added) 213 # 3210 (added size modulo 2**32 to the pyc header) 214 # Python 3.3a1 3220 (changed PEP 380 implementation) 215 # Python 3.3a4 3230 (revert changes to implicit __class__ closure) 216 # Python 3.4a1 3250 (evaluate positional default arguments before 217 # keyword-only defaults) 218 # Python 3.4a1 3260 (add LOAD_CLASSDEREF; allow locals of class to override 219 # free vars) 220 # Python 3.4a1 3270 (various tweaks to the __class__ closure) 221 # Python 3.4a1 3280 (remove implicit class argument) 222 # Python 3.4a4 3290 (changes to __qualname__ computation) 223 # Python 3.4a4 3300 (more changes to __qualname__ computation) 224 # Python 3.4rc2 3310 (alter __qualname__ computation) 225 # Python 3.5a0 3320 (matrix multiplication operator) 226 # Python 3.5b1 3330 (PEP 448: Additional Unpacking Generalizations) 227 # Python 3.5b2 3340 (fix dictionary display evaluation order #11205) 228 # Python 3.5b2 3350 (add GET_YIELD_FROM_ITER opcode #24400) 229 # Python 3.5.2 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286) 230 # Python 3.6a0 3360 (add FORMAT_VALUE opcode #25483 231 # Python 3.6a0 3361 (lineno delta of code.co_lnotab becomes signed) 232 # Python 3.6a1 3370 (16 bit wordcode) 233 # Python 3.6a1 3371 (add BUILD_CONST_KEY_MAP opcode #27140) 234 # Python 3.6a1 3372 (MAKE_FUNCTION simplification, remove MAKE_CLOSURE 235 # #27095) 236 # Python 3.6b1 3373 (add BUILD_STRING opcode #27078) 237 # Python 3.6b1 3375 (add SETUP_ANNOTATIONS and STORE_ANNOTATION opcodes 238 # #27985) 239 # Python 3.6b1 3376 (simplify CALL_FUNCTIONs & BUILD_MAP_UNPACK_WITH_CALL) 240 # Python 3.6b1 3377 (set __class__ cell from type.__new__ #23722) 241 # Python 3.6b2 3378 (add BUILD_TUPLE_UNPACK_WITH_CALL #28257) 242 # Python 3.6rc1 3379 (more thorough __class__ validation #23722) 243 # 244 # MAGIC must change whenever the bytecode emitted by the compiler may no 245 # longer be understood by older implementations of the eval loop (usually 246 # due to the addition of new opcodes). 247 # 248 # Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array 249 # in PC/launcher.c must also be updated. 250 251 MAGIC_NUMBER = (3379).to_bytes(2, 'little') + b'\r\n' 252 _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c 253 254 _PYCACHE = '__pycache__' 255 _OPT = 'opt-' 256 257 SOURCE_SUFFIXES = ['.py'] # _setup() adds .pyw as needed. 258 259 BYTECODE_SUFFIXES = ['.pyc'] 260 # Deprecated. 261 DEBUG_BYTECODE_SUFFIXES = OPTIMIZED_BYTECODE_SUFFIXES = BYTECODE_SUFFIXES 262 263 def cache_from_source(path, debug_override=None, *, optimization=None): 264 """Given the path to a .py file, return the path to its .pyc file. 265 266 The .py file does not need to exist; this simply returns the path to the 267 .pyc file calculated as if the .py file were imported. 268 269 The 'optimization' parameter controls the presumed optimization level of 270 the bytecode file. If 'optimization' is not None, the string representation 271 of the argument is taken and verified to be alphanumeric (else ValueError 272 is raised). 273 274 The debug_override parameter is deprecated. If debug_override is not None, 275 a True value is the same as setting 'optimization' to the empty string 276 while a False value is equivalent to setting 'optimization' to '1'. 277 278 If sys.implementation.cache_tag is None then NotImplementedError is raised. 279 280 """ 281 if debug_override is not None: 282 _warnings.warn('the debug_override parameter is deprecated; use ' 283 "'optimization' instead", DeprecationWarning) 284 if optimization is not None: 285 message = 'debug_override or optimization must be set to None' 286 raise TypeError(message) 287 optimization = '' if debug_override else 1 288 path = _os.fspath(path) 289 head, tail = _path_split(path) 290 base, sep, rest = tail.rpartition('.') 291 tag = sys.implementation.cache_tag 292 if tag is None: 293 raise NotImplementedError('sys.implementation.cache_tag is None') 294 almost_filename = ''.join([(base if base else rest), sep, tag]) 295 if optimization is None: 296 if sys.flags.optimize == 0: 297 optimization = '' 298 else: 299 optimization = sys.flags.optimize 300 optimization = str(optimization) 301 if optimization != '': 302 if not optimization.isalnum(): 303 raise ValueError('{!r} is not alphanumeric'.format(optimization)) 304 almost_filename = '{}.{}{}'.format(almost_filename, _OPT, optimization) 305 return _path_join(head, _PYCACHE, almost_filename + BYTECODE_SUFFIXES[0]) 306 307 308 def source_from_cache(path): 309 """Given the path to a .pyc. file, return the path to its .py file. 310 311 The .pyc file does not need to exist; this simply returns the path to 312 the .py file calculated to correspond to the .pyc file. If path does 313 not conform to PEP 3147/488 format, ValueError will be raised. If 314 sys.implementation.cache_tag is None then NotImplementedError is raised. 315 316 """ 317 if sys.implementation.cache_tag is None: 318 raise NotImplementedError('sys.implementation.cache_tag is None') 319 path = _os.fspath(path) 320 head, pycache_filename = _path_split(path) 321 head, pycache = _path_split(head) 322 if pycache != _PYCACHE: 323 raise ValueError('{} not bottom-level directory in ' 324 '{!r}'.format(_PYCACHE, path)) 325 dot_count = pycache_filename.count('.') 326 if dot_count not in {2, 3}: 327 raise ValueError('expected only 2 or 3 dots in ' 328 '{!r}'.format(pycache_filename)) 329 elif dot_count == 3: 330 optimization = pycache_filename.rsplit('.', 2)[-2] 331 if not optimization.startswith(_OPT): 332 raise ValueError("optimization portion of filename does not start " 333 "with {!r}".format(_OPT)) 334 opt_level = optimization[len(_OPT):] 335 if not opt_level.isalnum(): 336 raise ValueError("optimization level {!r} is not an alphanumeric " 337 "value".format(optimization)) 338 base_filename = pycache_filename.partition('.')[0] 339 return _path_join(head, base_filename + SOURCE_SUFFIXES[0]) 340 341 342 def _get_sourcefile(bytecode_path): 343 """Convert a bytecode file path to a source path (if possible). 344 345 This function exists purely for backwards-compatibility for 346 PyImport_ExecCodeModuleWithFilenames() in the C API. 347 348 """ 349 if len(bytecode_path) == 0: 350 return None 351 rest, _, extension = bytecode_path.rpartition('.') 352 if not rest or extension.lower()[-3:-1] != 'py': 353 return bytecode_path 354 try: 355 source_path = source_from_cache(bytecode_path) 356 except (NotImplementedError, ValueError): 357 source_path = bytecode_path[:-1] 358 return source_path if _path_isfile(source_path) else bytecode_path 359 360 361 def _get_cached(filename): 362 if filename.endswith(tuple(SOURCE_SUFFIXES)): 363 try: 364 return cache_from_source(filename) 365 except NotImplementedError: 366 pass 367 elif filename.endswith(tuple(BYTECODE_SUFFIXES)): 368 return filename 369 else: 370 return None 371 372 373 def _calc_mode(path): 374 """Calculate the mode permissions for a bytecode file.""" 375 try: 376 mode = _path_stat(path).st_mode 377 except OSError: 378 mode = 0o666 379 # We always ensure write access so we can update cached files 380 # later even when the source files are read-only on Windows (#6074) 381 mode |= 0o200 382 return mode 383 384 385 def _check_name(method): 386 """Decorator to verify that the module being requested matches the one the 387 loader can handle. 388 389 The first argument (self) must define _name which the second argument is 390 compared against. If the comparison fails then ImportError is raised. 391 392 """ 393 def _check_name_wrapper(self, name=None, *args, **kwargs): 394 if name is None: 395 name = self.name 396 elif self.name != name: 397 raise ImportError('loader for %s cannot handle %s' % 398 (self.name, name), name=name) 399 return method(self, name, *args, **kwargs) 400 try: 401 _wrap = _bootstrap._wrap 402 except NameError: 403 # XXX yuck 404 def _wrap(new, old): 405 for replace in ['__module__', '__name__', '__qualname__', '__doc__']: 406 if hasattr(old, replace): 407 setattr(new, replace, getattr(old, replace)) 408 new.__dict__.update(old.__dict__) 409 _wrap(_check_name_wrapper, method) 410 return _check_name_wrapper 411 412 413 def _find_module_shim(self, fullname): 414 """Try to find a loader for the specified module by delegating to 415 self.find_loader(). 416 417 This method is deprecated in favor of finder.find_spec(). 418 419 """ 420 # Call find_loader(). If it returns a string (indicating this 421 # is a namespace package portion), generate a warning and 422 # return None. 423 loader, portions = self.find_loader(fullname) 424 if loader is None and len(portions): 425 msg = 'Not importing directory {}: missing __init__' 426 _warnings.warn(msg.format(portions[0]), ImportWarning) 427 return loader 428 429 430 def _validate_bytecode_header(data, source_stats=None, name=None, path=None): 431 """Validate the header of the passed-in bytecode against source_stats (if 432 given) and returning the bytecode that can be compiled by compile(). 433 434 All other arguments are used to enhance error reporting. 435 436 ImportError is raised when the magic number is incorrect or the bytecode is 437 found to be stale. EOFError is raised when the data is found to be 438 truncated. 439 440 """ 441 exc_details = {} 442 if name is not None: 443 exc_details['name'] = name 444 else: 445 # To prevent having to make all messages have a conditional name. 446 name = '<bytecode>' 447 if path is not None: 448 exc_details['path'] = path 449 magic = data[:4] 450 raw_timestamp = data[4:8] 451 raw_size = data[8:12] 452 if magic != MAGIC_NUMBER: 453 message = 'bad magic number in {!r}: {!r}'.format(name, magic) 454 _bootstrap._verbose_message('{}', message) 455 raise ImportError(message, **exc_details) 456 elif len(raw_timestamp) != 4: 457 message = 'reached EOF while reading timestamp in {!r}'.format(name) 458 _bootstrap._verbose_message('{}', message) 459 raise EOFError(message) 460 elif len(raw_size) != 4: 461 message = 'reached EOF while reading size of source in {!r}'.format(name) 462 _bootstrap._verbose_message('{}', message) 463 raise EOFError(message) 464 if source_stats is not None: 465 try: 466 source_mtime = int(source_stats['mtime']) 467 except KeyError: 468 pass 469 else: 470 if _r_long(raw_timestamp) != source_mtime: 471 message = 'bytecode is stale for {!r}'.format(name) 472 _bootstrap._verbose_message('{}', message) 473 raise ImportError(message, **exc_details) 474 try: 475 source_size = source_stats['size'] & 0xFFFFFFFF 476 except KeyError: 477 pass 478 else: 479 if _r_long(raw_size) != source_size: 480 raise ImportError('bytecode is stale for {!r}'.format(name), 481 **exc_details) 482 return data[12:] 483 484 485 def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None): 486 """Compile bytecode as returned by _validate_bytecode_header().""" 487 code = marshal.loads(data) 488 if isinstance(code, _code_type): 489 _bootstrap._verbose_message('code object from {!r}', bytecode_path) 490 if source_path is not None: 491 _imp._fix_co_filename(code, source_path) 492 return code 493 else: 494 raise ImportError('Non-code object in {!r}'.format(bytecode_path), 495 name=name, path=bytecode_path) 496 497 def _code_to_bytecode(code, mtime=0, source_size=0): 498 """Compile a code object into bytecode for writing out to a byte-compiled 499 file.""" 500 data = bytearray(MAGIC_NUMBER) 501 data.extend(_w_long(mtime)) 502 data.extend(_w_long(source_size)) 503 data.extend(marshal.dumps(code)) 504 return data 505 506 507 def decode_source(source_bytes): 508 """Decode bytes representing source code and return the string. 509 510 Universal newline support is used in the decoding. 511 """ 512 import tokenize # To avoid bootstrap issues. 513 source_bytes_readline = _io.BytesIO(source_bytes).readline 514 encoding = tokenize.detect_encoding(source_bytes_readline) 515 newline_decoder = _io.IncrementalNewlineDecoder(None, True) 516 return newline_decoder.decode(source_bytes.decode(encoding[0])) 517 518 519 # Module specifications ####################################################### 520 521 _POPULATE = object() 522 523 524 def spec_from_file_location(name, location=None, *, loader=None, 525 submodule_search_locations=_POPULATE): 526 """Return a module spec based on a file location. 527 528 To indicate that the module is a package, set 529 submodule_search_locations to a list of directory paths. An 530 empty list is sufficient, though its not otherwise useful to the 531 import system. 532 533 The loader must take a spec as its only __init__() arg. 534 535 """ 536 if location is None: 537 # The caller may simply want a partially populated location- 538 # oriented spec. So we set the location to a bogus value and 539 # fill in as much as we can. 540 location = '<unknown>' 541 if hasattr(loader, 'get_filename'): 542 # ExecutionLoader 543 try: 544 location = loader.get_filename(name) 545 except ImportError: 546 pass 547 else: 548 location = _os.fspath(location) 549 550 # If the location is on the filesystem, but doesn't actually exist, 551 # we could return None here, indicating that the location is not 552 # valid. However, we don't have a good way of testing since an 553 # indirect location (e.g. a zip file or URL) will look like a 554 # non-existent file relative to the filesystem. 555 556 spec = _bootstrap.ModuleSpec(name, loader, origin=location) 557 spec._set_fileattr = True 558 559 # Pick a loader if one wasn't provided. 560 if loader is None: 561 for loader_class, suffixes in _get_supported_file_loaders(): 562 if location.endswith(tuple(suffixes)): 563 loader = loader_class(name, location) 564 spec.loader = loader 565 break 566 else: 567 return None 568 569 # Set submodule_search_paths appropriately. 570 if submodule_search_locations is _POPULATE: 571 # Check the loader. 572 if hasattr(loader, 'is_package'): 573 try: 574 is_package = loader.is_package(name) 575 except ImportError: 576 pass 577 else: 578 if is_package: 579 spec.submodule_search_locations = [] 580 else: 581 spec.submodule_search_locations = submodule_search_locations 582 if spec.submodule_search_locations == []: 583 if location: 584 dirname = _path_split(location)[0] 585 spec.submodule_search_locations.append(dirname) 586 587 return spec 588 589 590 # Loaders ##################################################################### 591 592 class WindowsRegistryFinder: 593 594 """Meta path finder for modules declared in the Windows registry.""" 595 596 REGISTRY_KEY = ( 597 'Software\\Python\\PythonCore\\{sys_version}' 598 '\\Modules\\{fullname}') 599 REGISTRY_KEY_DEBUG = ( 600 'Software\\Python\\PythonCore\\{sys_version}' 601 '\\Modules\\{fullname}\\Debug') 602 DEBUG_BUILD = False # Changed in _setup() 603 604 @classmethod 605 def _open_registry(cls, key): 606 try: 607 return _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, key) 608 except OSError: 609 return _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, key) 610 611 @classmethod 612 def _search_registry(cls, fullname): 613 if cls.DEBUG_BUILD: 614 registry_key = cls.REGISTRY_KEY_DEBUG 615 else: 616 registry_key = cls.REGISTRY_KEY 617 key = registry_key.format(fullname=fullname, 618 sys_version='%d.%d' % sys.version_info[:2]) 619 try: 620 with cls._open_registry(key) as hkey: 621 filepath = _winreg.QueryValue(hkey, '') 622 except OSError: 623 return None 624 return filepath 625 626 @classmethod 627 def find_spec(cls, fullname, path=None, target=None): 628 filepath = cls._search_registry(fullname) 629 if filepath is None: 630 return None 631 try: 632 _path_stat(filepath) 633 except OSError: 634 return None 635 for loader, suffixes in _get_supported_file_loaders(): 636 if filepath.endswith(tuple(suffixes)): 637 spec = _bootstrap.spec_from_loader(fullname, 638 loader(fullname, filepath), 639 origin=filepath) 640 return spec 641 642 @classmethod 643 def find_module(cls, fullname, path=None): 644 """Find module named in the registry. 645 646 This method is deprecated. Use exec_module() instead. 647 648 """ 649 spec = cls.find_spec(fullname, path) 650 if spec is not None: 651 return spec.loader 652 else: 653 return None 654 655 656 class _LoaderBasics: 657 658 """Base class of common code needed by both SourceLoader and 659 SourcelessFileLoader.""" 660 661 def is_package(self, fullname): 662 """Concrete implementation of InspectLoader.is_package by checking if 663 the path returned by get_filename has a filename of '__init__.py'.""" 664 filename = _path_split(self.get_filename(fullname))[1] 665 filename_base = filename.rsplit('.', 1)[0] 666 tail_name = fullname.rpartition('.')[2] 667 return filename_base == '__init__' and tail_name != '__init__' 668 669 def create_module(self, spec): 670 """Use default semantics for module creation.""" 671 672 def exec_module(self, module): 673 """Execute the module.""" 674 code = self.get_code(module.__name__) 675 if code is None: 676 raise ImportError('cannot load module {!r} when get_code() ' 677 'returns None'.format(module.__name__)) 678 _bootstrap._call_with_frames_removed(exec, code, module.__dict__) 679 680 def load_module(self, fullname): 681 """This module is deprecated.""" 682 return _bootstrap._load_module_shim(self, fullname) 683 684 685 class SourceLoader(_LoaderBasics): 686 687 def path_mtime(self, path): 688 """Optional method that returns the modification time (an int) for the 689 specified path, where path is a str. 690 691 Raises IOError when the path cannot be handled. 692 """ 693 raise IOError 694 695 def path_stats(self, path): 696 """Optional method returning a metadata dict for the specified path 697 to by the path (str). 698 Possible keys: 699 - 'mtime' (mandatory) is the numeric timestamp of last source 700 code modification; 701 - 'size' (optional) is the size in bytes of the source code. 702 703 Implementing this method allows the loader to read bytecode files. 704 Raises IOError when the path cannot be handled. 705 """ 706 return {'mtime': self.path_mtime(path)} 707 708 def _cache_bytecode(self, source_path, cache_path, data): 709 """Optional method which writes data (bytes) to a file path (a str). 710 711 Implementing this method allows for the writing of bytecode files. 712 713 The source path is needed in order to correctly transfer permissions 714 """ 715 # For backwards compatibility, we delegate to set_data() 716 return self.set_data(cache_path, data) 717 718 def set_data(self, path, data): 719 """Optional method which writes data (bytes) to a file path (a str). 720 721 Implementing this method allows for the writing of bytecode files. 722 """ 723 724 725 def get_source(self, fullname): 726 """Concrete implementation of InspectLoader.get_source.""" 727 path = self.get_filename(fullname) 728 try: 729 source_bytes = self.get_data(path) 730 except OSError as exc: 731 raise ImportError('source not available through get_data()', 732 name=fullname) from exc 733 return decode_source(source_bytes) 734 735 def source_to_code(self, data, path, *, _optimize=-1): 736 """Return the code object compiled from source. 737 738 The 'data' argument can be any object type that compile() supports. 739 """ 740 return _bootstrap._call_with_frames_removed(compile, data, path, 'exec', 741 dont_inherit=True, optimize=_optimize) 742 743 def get_code(self, fullname): 744 """Concrete implementation of InspectLoader.get_code. 745 746 Reading of bytecode requires path_stats to be implemented. To write 747 bytecode, set_data must also be implemented. 748 749 """ 750 source_path = self.get_filename(fullname) 751 source_mtime = None 752 try: 753 bytecode_path = cache_from_source(source_path) 754 except NotImplementedError: 755 bytecode_path = None 756 else: 757 try: 758 st = self.path_stats(source_path) 759 except IOError: 760 pass 761 else: 762 source_mtime = int(st['mtime']) 763 try: 764 data = self.get_data(bytecode_path) 765 except OSError: 766 pass 767 else: 768 try: 769 bytes_data = _validate_bytecode_header(data, 770 source_stats=st, name=fullname, 771 path=bytecode_path) 772 except (ImportError, EOFError): 773 pass 774 else: 775 _bootstrap._verbose_message('{} matches {}', bytecode_path, 776 source_path) 777 return _compile_bytecode(bytes_data, name=fullname, 778 bytecode_path=bytecode_path, 779 source_path=source_path) 780 source_bytes = self.get_data(source_path) 781 code_object = self.source_to_code(source_bytes, source_path) 782 _bootstrap._verbose_message('code object from {}', source_path) 783 if (not sys.dont_write_bytecode and bytecode_path is not None and 784 source_mtime is not None): 785 data = _code_to_bytecode(code_object, source_mtime, 786 len(source_bytes)) 787 try: 788 self._cache_bytecode(source_path, bytecode_path, data) 789 _bootstrap._verbose_message('wrote {!r}', bytecode_path) 790 except NotImplementedError: 791 pass 792 return code_object 793 794 795 class FileLoader: 796 797 """Base file loader class which implements the loader protocol methods that 798 require file system usage.""" 799 800 def __init__(self, fullname, path): 801 """Cache the module name and the path to the file found by the 802 finder.""" 803 self.name = fullname 804 self.path = path 805 806 def __eq__(self, other): 807 return (self.__class__ == other.__class__ and 808 self.__dict__ == other.__dict__) 809 810 def __hash__(self): 811 return hash(self.name) ^ hash(self.path) 812 813 @_check_name 814 def load_module(self, fullname): 815 """Load a module from a file. 816 817 This method is deprecated. Use exec_module() instead. 818 819 """ 820 # The only reason for this method is for the name check. 821 # Issue #14857: Avoid the zero-argument form of super so the implementation 822 # of that form can be updated without breaking the frozen module 823 return super(FileLoader, self).load_module(fullname) 824 825 @_check_name 826 def get_filename(self, fullname): 827 """Return the path to the source file as found by the finder.""" 828 return self.path 829 830 def get_data(self, path): 831 """Return the data from path as raw bytes.""" 832 with _io.FileIO(path, 'r') as file: 833 return file.read() 834 835 836 class SourceFileLoader(FileLoader, SourceLoader): 837 838 """Concrete implementation of SourceLoader using the file system.""" 839 840 def path_stats(self, path): 841 """Return the metadata for the path.""" 842 st = _path_stat(path) 843 return {'mtime': st.st_mtime, 'size': st.st_size} 844 845 def _cache_bytecode(self, source_path, bytecode_path, data): 846 # Adapt between the two APIs 847 mode = _calc_mode(source_path) 848 return self.set_data(bytecode_path, data, _mode=mode) 849 850 def set_data(self, path, data, *, _mode=0o666): 851 """Write bytes data to a file.""" 852 parent, filename = _path_split(path) 853 path_parts = [] 854 # Figure out what directories are missing. 855 while parent and not _path_isdir(parent): 856 parent, part = _path_split(parent) 857 path_parts.append(part) 858 # Create needed directories. 859 for part in reversed(path_parts): 860 parent = _path_join(parent, part) 861 try: 862 _os.mkdir(parent) 863 except FileExistsError: 864 # Probably another Python process already created the dir. 865 continue 866 except OSError as exc: 867 # Could be a permission error, read-only filesystem: just forget 868 # about writing the data. 869 _bootstrap._verbose_message('could not create {!r}: {!r}', 870 parent, exc) 871 return 872 try: 873 _write_atomic(path, data, _mode) 874 _bootstrap._verbose_message('created {!r}', path) 875 except OSError as exc: 876 # Same as above: just don't write the bytecode. 877 _bootstrap._verbose_message('could not create {!r}: {!r}', path, 878 exc) 879 880 881 class SourcelessFileLoader(FileLoader, _LoaderBasics): 882 883 """Loader which handles sourceless file imports.""" 884 885 def get_code(self, fullname): 886 path = self.get_filename(fullname) 887 data = self.get_data(path) 888 bytes_data = _validate_bytecode_header(data, name=fullname, path=path) 889 return _compile_bytecode(bytes_data, name=fullname, bytecode_path=path) 890 891 def get_source(self, fullname): 892 """Return None as there is no source code.""" 893 return None 894 895 896 # Filled in by _setup(). 897 EXTENSION_SUFFIXES = [] 898 899 900 class ExtensionFileLoader(FileLoader, _LoaderBasics): 901 902 """Loader for extension modules. 903 904 The constructor is designed to work with FileFinder. 905 906 """ 907 908 def __init__(self, name, path): 909 self.name = name 910 self.path = path 911 912 def __eq__(self, other): 913 return (self.__class__ == other.__class__ and 914 self.__dict__ == other.__dict__) 915 916 def __hash__(self): 917 return hash(self.name) ^ hash(self.path) 918 919 def create_module(self, spec): 920 """Create an unitialized extension module""" 921 module = _bootstrap._call_with_frames_removed( 922 _imp.create_dynamic, spec) 923 _bootstrap._verbose_message('extension module {!r} loaded from {!r}', 924 spec.name, self.path) 925 return module 926 927 def exec_module(self, module): 928 """Initialize an extension module""" 929 _bootstrap._call_with_frames_removed(_imp.exec_dynamic, module) 930 _bootstrap._verbose_message('extension module {!r} executed from {!r}', 931 self.name, self.path) 932 933 def is_package(self, fullname): 934 """Return True if the extension module is a package.""" 935 file_name = _path_split(self.path)[1] 936 return any(file_name == '__init__' + suffix 937 for suffix in EXTENSION_SUFFIXES) 938 939 def get_code(self, fullname): 940 """Return None as an extension module cannot create a code object.""" 941 return None 942 943 def get_source(self, fullname): 944 """Return None as extension modules have no source code.""" 945 return None 946 947 @_check_name 948 def get_filename(self, fullname): 949 """Return the path to the source file as found by the finder.""" 950 return self.path 951 952 953 class _NamespacePath: 954 """Represents a namespace package's path. It uses the module name 955 to find its parent module, and from there it looks up the parent's 956 __path__. When this changes, the module's own path is recomputed, 957 using path_finder. For top-level modules, the parent module's path 958 is sys.path.""" 959 960 def __init__(self, name, path, path_finder): 961 self._name = name 962 self._path = path 963 self._last_parent_path = tuple(self._get_parent_path()) 964 self._path_finder = path_finder 965 966 def _find_parent_path_names(self): 967 """Returns a tuple of (parent-module-name, parent-path-attr-name)""" 968 parent, dot, me = self._name.rpartition('.') 969 if dot == '': 970 # This is a top-level module. sys.path contains the parent path. 971 return 'sys', 'path' 972 # Not a top-level module. parent-module.__path__ contains the 973 # parent path. 974 return parent, '__path__' 975 976 def _get_parent_path(self): 977 parent_module_name, path_attr_name = self._find_parent_path_names() 978 return getattr(sys.modules[parent_module_name], path_attr_name) 979 980 def _recalculate(self): 981 # If the parent's path has changed, recalculate _path 982 parent_path = tuple(self._get_parent_path()) # Make a copy 983 if parent_path != self._last_parent_path: 984 spec = self._path_finder(self._name, parent_path) 985 # Note that no changes are made if a loader is returned, but we 986 # do remember the new parent path 987 if spec is not None and spec.loader is None: 988 if spec.submodule_search_locations: 989 self._path = spec.submodule_search_locations 990 self._last_parent_path = parent_path # Save the copy 991 return self._path 992 993 def __iter__(self): 994 return iter(self._recalculate()) 995 996 def __setitem__(self, index, path): 997 self._path[index] = path 998 999 def __len__(self): 1000 return len(self._recalculate()) 1001 1002 def __repr__(self): 1003 return '_NamespacePath({!r})'.format(self._path) 1004 1005 def __contains__(self, item): 1006 return item in self._recalculate() 1007 1008 def append(self, item): 1009 self._path.append(item) 1010 1011 1012 # We use this exclusively in module_from_spec() for backward-compatibility. 1013 class _NamespaceLoader: 1014 def __init__(self, name, path, path_finder): 1015 self._path = _NamespacePath(name, path, path_finder) 1016 1017 @classmethod 1018 def module_repr(cls, module): 1019 """Return repr for the module. 1020 1021 The method is deprecated. The import machinery does the job itself. 1022 1023 """ 1024 return '<module {!r} (namespace)>'.format(module.__name__) 1025 1026 def is_package(self, fullname): 1027 return True 1028 1029 def get_source(self, fullname): 1030 return '' 1031 1032 def get_code(self, fullname): 1033 return compile('', '<string>', 'exec', dont_inherit=True) 1034 1035 def create_module(self, spec): 1036 """Use default semantics for module creation.""" 1037 1038 def exec_module(self, module): 1039 pass 1040 1041 def load_module(self, fullname): 1042 """Load a namespace module. 1043 1044 This method is deprecated. Use exec_module() instead. 1045 1046 """ 1047 # The import system never calls this method. 1048 _bootstrap._verbose_message('namespace module loaded with path {!r}', 1049 self._path) 1050 return _bootstrap._load_module_shim(self, fullname) 1051 1052 1053 # Finders ##################################################################### 1054 1055 class PathFinder: 1056 1057 """Meta path finder for sys.path and package __path__ attributes.""" 1058 1059 @classmethod 1060 def invalidate_caches(cls): 1061 """Call the invalidate_caches() method on all path entry finders 1062 stored in sys.path_importer_caches (where implemented).""" 1063 for finder in sys.path_importer_cache.values(): 1064 if hasattr(finder, 'invalidate_caches'): 1065 finder.invalidate_caches() 1066 1067 @classmethod 1068 def _path_hooks(cls, path): 1069 """Search sys.path_hooks for a finder for 'path'.""" 1070 if sys.path_hooks is not None and not sys.path_hooks: 1071 _warnings.warn('sys.path_hooks is empty', ImportWarning) 1072 for hook in sys.path_hooks: 1073 try: 1074 return hook(path) 1075 except ImportError: 1076 continue 1077 else: 1078 return None 1079 1080 @classmethod 1081 def _path_importer_cache(cls, path): 1082 """Get the finder for the path entry from sys.path_importer_cache. 1083 1084 If the path entry is not in the cache, find the appropriate finder 1085 and cache it. If no finder is available, store None. 1086 1087 """ 1088 if path == '': 1089 try: 1090 path = _os.getcwd() 1091 except FileNotFoundError: 1092 # Don't cache the failure as the cwd can easily change to 1093 # a valid directory later on. 1094 return None 1095 try: 1096 finder = sys.path_importer_cache[path] 1097 except KeyError: 1098 finder = cls._path_hooks(path) 1099 sys.path_importer_cache[path] = finder 1100 return finder 1101 1102 @classmethod 1103 def _legacy_get_spec(cls, fullname, finder): 1104 # This would be a good place for a DeprecationWarning if 1105 # we ended up going that route. 1106 if hasattr(finder, 'find_loader'): 1107 loader, portions = finder.find_loader(fullname) 1108 else: 1109 loader = finder.find_module(fullname) 1110 portions = [] 1111 if loader is not None: 1112 return _bootstrap.spec_from_loader(fullname, loader) 1113 spec = _bootstrap.ModuleSpec(fullname, None) 1114 spec.submodule_search_locations = portions 1115 return spec 1116 1117 @classmethod 1118 def _get_spec(cls, fullname, path, target=None): 1119 """Find the loader or namespace_path for this module/package name.""" 1120 # If this ends up being a namespace package, namespace_path is 1121 # the list of paths that will become its __path__ 1122 namespace_path = [] 1123 for entry in path: 1124 if not isinstance(entry, (str, bytes)): 1125 continue 1126 finder = cls._path_importer_cache(entry) 1127 if finder is not None: 1128 if hasattr(finder, 'find_spec'): 1129 spec = finder.find_spec(fullname, target) 1130 else: 1131 spec = cls._legacy_get_spec(fullname, finder) 1132 if spec is None: 1133 continue 1134 if spec.loader is not None: 1135 return spec 1136 portions = spec.submodule_search_locations 1137 if portions is None: 1138 raise ImportError('spec missing loader') 1139 # This is possibly part of a namespace package. 1140 # Remember these path entries (if any) for when we 1141 # create a namespace package, and continue iterating 1142 # on path. 1143 namespace_path.extend(portions) 1144 else: 1145 spec = _bootstrap.ModuleSpec(fullname, None) 1146 spec.submodule_search_locations = namespace_path 1147 return spec 1148 1149 @classmethod 1150 def find_spec(cls, fullname, path=None, target=None): 1151 """Try to find a spec for 'fullname' on sys.path or 'path'. 1152 1153 The search is based on sys.path_hooks and sys.path_importer_cache. 1154 """ 1155 if path is None: 1156 path = sys.path 1157 spec = cls._get_spec(fullname, path, target) 1158 if spec is None: 1159 return None 1160 elif spec.loader is None: 1161 namespace_path = spec.submodule_search_locations 1162 if namespace_path: 1163 # We found at least one namespace path. Return a 1164 # spec which can create the namespace package. 1165 spec.origin = 'namespace' 1166 spec.submodule_search_locations = _NamespacePath(fullname, namespace_path, cls._get_spec) 1167 return spec 1168 else: 1169 return None 1170 else: 1171 return spec 1172 1173 @classmethod 1174 def find_module(cls, fullname, path=None): 1175 """find the module on sys.path or 'path' based on sys.path_hooks and 1176 sys.path_importer_cache. 1177 1178 This method is deprecated. Use find_spec() instead. 1179 1180 """ 1181 spec = cls.find_spec(fullname, path) 1182 if spec is None: 1183 return None 1184 return spec.loader 1185 1186 1187 class FileFinder: 1188 1189 """File-based finder. 1190 1191 Interactions with the file system are cached for performance, being 1192 refreshed when the directory the finder is handling has been modified. 1193 1194 """ 1195 1196 def __init__(self, path, *loader_details): 1197 """Initialize with the path to search on and a variable number of 1198 2-tuples containing the loader and the file suffixes the loader 1199 recognizes.""" 1200 loaders = [] 1201 for loader, suffixes in loader_details: 1202 loaders.extend((suffix, loader) for suffix in suffixes) 1203 self._loaders = loaders 1204 # Base (directory) path 1205 self.path = path or '.' 1206 self._path_mtime = -1 1207 self._path_cache = set() 1208 self._relaxed_path_cache = set() 1209 1210 def invalidate_caches(self): 1211 """Invalidate the directory mtime.""" 1212 self._path_mtime = -1 1213 1214 find_module = _find_module_shim 1215 1216 def find_loader(self, fullname): 1217 """Try to find a loader for the specified module, or the namespace 1218 package portions. Returns (loader, list-of-portions). 1219 1220 This method is deprecated. Use find_spec() instead. 1221 1222 """ 1223 spec = self.find_spec(fullname) 1224 if spec is None: 1225 return None, [] 1226 return spec.loader, spec.submodule_search_locations or [] 1227 1228 def _get_spec(self, loader_class, fullname, path, smsl, target): 1229 loader = loader_class(fullname, path) 1230 return spec_from_file_location(fullname, path, loader=loader, 1231 submodule_search_locations=smsl) 1232 1233 def find_spec(self, fullname, target=None): 1234 """Try to find a spec for the specified module. 1235 1236 Returns the matching spec, or None if not found. 1237 """ 1238 is_namespace = False 1239 tail_module = fullname.rpartition('.')[2] 1240 try: 1241 mtime = _path_stat(self.path or _os.getcwd()).st_mtime 1242 except OSError: 1243 mtime = -1 1244 if mtime != self._path_mtime: 1245 self._fill_cache() 1246 self._path_mtime = mtime 1247 # tail_module keeps the original casing, for __file__ and friends 1248 if _relax_case(): 1249 cache = self._relaxed_path_cache 1250 cache_module = tail_module.lower() 1251 else: 1252 cache = self._path_cache 1253 cache_module = tail_module 1254 # Check if the module is the name of a directory (and thus a package). 1255 if cache_module in cache: 1256 base_path = _path_join(self.path, tail_module) 1257 for suffix, loader_class in self._loaders: 1258 init_filename = '__init__' + suffix 1259 full_path = _path_join(base_path, init_filename) 1260 if _path_isfile(full_path): 1261 return self._get_spec(loader_class, fullname, full_path, [base_path], target) 1262 else: 1263 # If a namespace package, return the path if we don't 1264 # find a module in the next section. 1265 is_namespace = _path_isdir(base_path) 1266 # Check for a file w/ a proper suffix exists. 1267 for suffix, loader_class in self._loaders: 1268 full_path = _path_join(self.path, tail_module + suffix) 1269 _bootstrap._verbose_message('trying {}', full_path, verbosity=2) 1270 if cache_module + suffix in cache: 1271 if _path_isfile(full_path): 1272 return self._get_spec(loader_class, fullname, full_path, 1273 None, target) 1274 if is_namespace: 1275 _bootstrap._verbose_message('possible namespace for {}', base_path) 1276 spec = _bootstrap.ModuleSpec(fullname, None) 1277 spec.submodule_search_locations = [base_path] 1278 return spec 1279 return None 1280 1281 def _fill_cache(self): 1282 """Fill the cache of potential modules and packages for this directory.""" 1283 path = self.path 1284 try: 1285 contents = _os.listdir(path or _os.getcwd()) 1286 except (FileNotFoundError, PermissionError, NotADirectoryError): 1287 # Directory has either been removed, turned into a file, or made 1288 # unreadable. 1289 contents = [] 1290 # We store two cached versions, to handle runtime changes of the 1291 # PYTHONCASEOK environment variable. 1292 if not sys.platform.startswith('win'): 1293 self._path_cache = set(contents) 1294 else: 1295 # Windows users can import modules with case-insensitive file 1296 # suffixes (for legacy reasons). Make the suffix lowercase here 1297 # so it's done once instead of for every import. This is safe as 1298 # the specified suffixes to check against are always specified in a 1299 # case-sensitive manner. 1300 lower_suffix_contents = set() 1301 for item in contents: 1302 name, dot, suffix = item.partition('.') 1303 if dot: 1304 new_name = '{}.{}'.format(name, suffix.lower()) 1305 else: 1306 new_name = name 1307 lower_suffix_contents.add(new_name) 1308 self._path_cache = lower_suffix_contents 1309 if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): 1310 self._relaxed_path_cache = {fn.lower() for fn in contents} 1311 1312 @classmethod 1313 def path_hook(cls, *loader_details): 1314 """A class method which returns a closure to use on sys.path_hook 1315 which will return an instance using the specified loaders and the path 1316 called on the closure. 1317 1318 If the path called on the closure is not a directory, ImportError is 1319 raised. 1320 1321 """ 1322 def path_hook_for_FileFinder(path): 1323 """Path hook for importlib.machinery.FileFinder.""" 1324 if not _path_isdir(path): 1325 raise ImportError('only directories are supported', path=path) 1326 return cls(path, *loader_details) 1327 1328 return path_hook_for_FileFinder 1329 1330 def __repr__(self): 1331 return 'FileFinder({!r})'.format(self.path) 1332 1333 1334 # Import setup ############################################################### 1335 1336 def _fix_up_module(ns, name, pathname, cpathname=None): 1337 # This function is used by PyImport_ExecCodeModuleObject(). 1338 loader = ns.get('__loader__') 1339 spec = ns.get('__spec__') 1340 if not loader: 1341 if spec: 1342 loader = spec.loader 1343 elif pathname == cpathname: 1344 loader = SourcelessFileLoader(name, pathname) 1345 else: 1346 loader = SourceFileLoader(name, pathname) 1347 if not spec: 1348 spec = spec_from_file_location(name, pathname, loader=loader) 1349 try: 1350 ns['__spec__'] = spec 1351 ns['__loader__'] = loader 1352 ns['__file__'] = pathname 1353 ns['__cached__'] = cpathname 1354 except Exception: 1355 # Not important enough to report. 1356 pass 1357 1358 1359 def _get_supported_file_loaders(): 1360 """Returns a list of file-based module loaders. 1361 1362 Each item is a tuple (loader, suffixes). 1363 """ 1364 extensions = ExtensionFileLoader, _imp.extension_suffixes() 1365 source = SourceFileLoader, SOURCE_SUFFIXES 1366 bytecode = SourcelessFileLoader, BYTECODE_SUFFIXES 1367 return [extensions, source, bytecode] 1368 1369 1370 def _setup(_bootstrap_module): 1371 """Setup the path-based importers for importlib by importing needed 1372 built-in modules and injecting them into the global namespace. 1373 1374 Other components are extracted from the core bootstrap module. 1375 1376 """ 1377 global sys, _imp, _bootstrap 1378 _bootstrap = _bootstrap_module 1379 sys = _bootstrap.sys 1380 _imp = _bootstrap._imp 1381 1382 # Directly load built-in modules needed during bootstrap. 1383 self_module = sys.modules[__name__] 1384 for builtin_name in ('_io', '_warnings', 'builtins', 'marshal'): 1385 if builtin_name not in sys.modules: 1386 builtin_module = _bootstrap._builtin_from_name(builtin_name) 1387 else: 1388 builtin_module = sys.modules[builtin_name] 1389 setattr(self_module, builtin_name, builtin_module) 1390 1391 # Directly load the os module (needed during bootstrap). 1392 os_details = ('posix', ['/']), ('nt', ['\\', '/']) 1393 for builtin_os, path_separators in os_details: 1394 # Assumption made in _path_join() 1395 assert all(len(sep) == 1 for sep in path_separators) 1396 path_sep = path_separators[0] 1397 if builtin_os in sys.modules: 1398 os_module = sys.modules[builtin_os] 1399 break 1400 else: 1401 try: 1402 os_module = _bootstrap._builtin_from_name(builtin_os) 1403 break 1404 except ImportError: 1405 continue 1406 else: 1407 raise ImportError('importlib requires posix or nt') 1408 setattr(self_module, '_os', os_module) 1409 setattr(self_module, 'path_sep', path_sep) 1410 setattr(self_module, 'path_separators', ''.join(path_separators)) 1411 1412 # Directly load the _thread module (needed during bootstrap). 1413 try: 1414 thread_module = _bootstrap._builtin_from_name('_thread') 1415 except ImportError: 1416 # Python was built without threads 1417 thread_module = None 1418 setattr(self_module, '_thread', thread_module) 1419 1420 # Directly load the _weakref module (needed during bootstrap). 1421 weakref_module = _bootstrap._builtin_from_name('_weakref') 1422 setattr(self_module, '_weakref', weakref_module) 1423 1424 # Directly load the winreg module (needed during bootstrap). 1425 if builtin_os == 'nt': 1426 winreg_module = _bootstrap._builtin_from_name('winreg') 1427 setattr(self_module, '_winreg', winreg_module) 1428 1429 # Constants 1430 setattr(self_module, '_relax_case', _make_relax_case()) 1431 EXTENSION_SUFFIXES.extend(_imp.extension_suffixes()) 1432 if builtin_os == 'nt': 1433 SOURCE_SUFFIXES.append('.pyw') 1434 if '_d.pyd' in EXTENSION_SUFFIXES: 1435 WindowsRegistryFinder.DEBUG_BUILD = True 1436 1437 1438 def _install(_bootstrap_module): 1439 """Install the path-based import components.""" 1440 _setup(_bootstrap_module) 1441 supported_loaders = _get_supported_file_loaders() 1442 sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders)]) 1443 sys.meta_path.append(PathFinder) 1444
