"""Core implementation of path-based import.

This module is NOT meant to be directly imported! It has been designed such

that it can be bootstrapped into Python as the implementation of import. As

such it requires the injection of specific modules and attributes in order to

work. One should use importlib as the public-facing version of this module.

"""

# IMPORTANT: Whenever making changes to this module, be sure to run a top-level

# `make regen-importlib` followed by `make` in order to get the frozen version

# of the module updated. Not doing so will result in the Makefile to fail for

# all others who don't have a ./python around to freeze the module in the early

# stages of compilation.

#

# See importlib._setup() for what is injected into the global namespace.

# When editing this code be aware that code executed at import time CANNOT

# reference any injected objects! This includes not only global code but also

# anything specified at the class level.

# Module injected manually by _set_bootstrap_module()

_bootstrap = None

# Import builtin modules

import _imp

import _io

import sys

import _warnings

import marshal

_MS_WINDOWS = (sys.platform == 'win32')

if _MS_WINDOWS:

import nt as _os

import winreg

else:

import posix as _os

if _MS_WINDOWS:

path_separators = ['\\', '/']

else:

path_separators = ['/']

# Assumption made in _path_join()

assert all(len(sep) == 1 for sep in path_separators)

path_sep = path_separators[0]

path_sep_tuple = tuple(path_separators)

path_separators = ''.join(path_separators)

_pathseps_with_colon = {f':{s}' for s in path_separators}

# Bootstrap-related code ######################################################

_CASE_INSENSITIVE_PLATFORMS_STR_KEY = 'win',

_CASE_INSENSITIVE_PLATFORMS_BYTES_KEY = 'cygwin', 'darwin'

_CASE_INSENSITIVE_PLATFORMS = (_CASE_INSENSITIVE_PLATFORMS_BYTES_KEY

+ _CASE_INSENSITIVE_PLATFORMS_STR_KEY)

def _make_relax_case():

if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS):

if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS_STR_KEY):

key = 'PYTHONCASEOK'

else:

key = b'PYTHONCASEOK'

def _relax_case():

"""True if filenames must be checked case-insensitively and ignore environment flags are not set."""

return not sys.flags.ignore_environment and key in _os.environ

else:

def _relax_case():

"""True if filenames must be checked case-insensitively."""

return False

return _relax_case

_relax_case = _make_relax_case()

def _pack_uint32(x):

"""Convert a 32-bit integer to little-endian."""

return (int(x) & 0xFFFFFFFF).to_bytes(4, 'little')

def _unpack_uint32(data):

"""Convert 4 bytes in little-endian to an integer."""

assert len(data) == 4

return int.from_bytes(data, 'little')

def _unpack_uint16(data):

"""Convert 2 bytes in little-endian to an integer."""

assert len(data) == 2

return int.from_bytes(data, 'little')

if _MS_WINDOWS:

def _path_join(*path_parts):

"""Replacement for os.path.join()."""

if not path_parts:

return ""

if len(path_parts) == 1:

return path_parts[0]

root = ""

path = []

for new_root, tail in map(_os._path_splitroot, path_parts):

if new_root.startswith(path_sep_tuple) or new_root.endswith(path_sep_tuple):

root = new_root.rstrip(path_separators) or root

path = [path_sep + tail]

elif new_root.endswith(':'):

if root.casefold() != new_root.casefold():

# Drive relative paths have to be resolved by the OS, so we reset the

# tail but do not add a path_sep prefix.

root = new_root

path = [tail]

else:

path.append(tail)

else:

root = new_root or root

path.append(tail)

path = [p.rstrip(path_separators) for p in path if p]

if len(path) == 1 and not path[0]:

# Avoid losing the root's trailing separator when joining with nothing

return root + path_sep

return root + path_sep.join(path)

else:

def _path_join(*path_parts):

"""Replacement for os.path.join()."""

return path_sep.join([part.rstrip(path_separators)

for part in path_parts if part])

def _path_split(path):

"""Replacement for os.path.split()."""

i = max(path.rfind(p) for p in path_separators)

if i < 0:

return '', path

return path[:i], path[i + 1:]

def _path_stat(path):

"""Stat the path.

Made a separate function to make it easier to override in experiments

(e.g. cache stat results).

"""

return _os.stat(path)

def _path_is_mode_type(path, mode):

"""Test whether the path is the specified mode type."""

try:

stat_info = _path_stat(path)

except OSError:

return False

return (stat_info.st_mode & 0o170000) == mode

def _path_isfile(path):

"""Replacement for os.path.isfile."""

return _path_is_mode_type(path, 0o100000)

def _path_isdir(path):

"""Replacement for os.path.isdir."""

if not path:

path = _os.getcwd()

return _path_is_mode_type(path, 0o040000)

if _MS_WINDOWS:

def _path_isabs(path):

"""Replacement for os.path.isabs."""

if not path:

return False

root = _os._path_splitroot(path)[0].replace('/', '\\')

return len(root) > 1 and (root.startswith('\\\\') or root.endswith('\\'))

else:

def _path_isabs(path):

"""Replacement for os.path.isabs."""

return path.startswith(path_separators)

def _path_abspath(path):

"""Replacement for os.path.abspath."""

if not _path_isabs(path):

for sep in path_separators:

path = path.removeprefix(f".{sep}")

return _path_join(_os.getcwd(), path)

else:

return path

def _write_atomic(path, data, mode=0o666):

"""Best-effort function to write data to a path atomically.

Be prepared to handle a FileExistsError if concurrent writing of the

temporary file is attempted."""

# id() is used to generate a pseudo-random filename.

path_tmp = f'{path}.{id(path)}'

fd = _os.open(path_tmp,

_os.O_EXCL | _os.O_CREAT | _os.O_WRONLY, mode & 0o666)

try:

# We first write data to a temporary file, and then use os.replace() to

# perform an atomic rename.

with _io.FileIO(fd, 'wb') as file:

bytes_written = file.write(data)

if bytes_written != len(data):

# Raise an OSError so the 'except' below cleans up the partially

# written file.

raise OSError("os.write() didn't write the full pyc file")

_os.replace(path_tmp, path)

except OSError:

try:

_os.unlink(path_tmp)

except OSError:

pass

raise

_code_type = type(_write_atomic.__code__)

# Finder/loader utility code ###############################################

# Magic word to reject .pyc files generated by other Python versions.

# It should change for each incompatible change to the bytecode.

#

# The value of CR and LF is incorporated so if you ever read or write

# a .pyc file in text mode the magic number will be wrong; also, the

# Apple MPW compiler swaps their values, botching string constants.

#

# There were a variety of old schemes for setting the magic number.

# The current working scheme is to increment the previous value by

# 10.

#

# Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic

# number also includes a new "magic tag", i.e. a human readable string used

# to represent the magic number in __pycache__ directories. When you change

# the magic number, you must also set a new unique magic tag. Generally this

# can be named after the Python major version of the magic number bump, but

# it can really be anything, as long as it's different than anything else

# that's come before. The tags are included in the following table, starting

# with Python 3.2a0.

#

# Known values:

# Python 1.5: 20121

# Python 1.5.1: 20121

# Python 1.5.2: 20121

# Python 1.6: 50428

# Python 2.0: 50823

# Python 2.0.1: 50823

# Python 2.1: 60202

# Python 2.1.1: 60202

# Python 2.1.2: 60202

# Python 2.2: 60717

# Python 2.3a0: 62011

# Python 2.3a0: 62021

# Python 2.3a0: 62011 (!)

# Python 2.4a0: 62041

# Python 2.4a3: 62051

# Python 2.4b1: 62061

# Python 2.5a0: 62071

# Python 2.5a0: 62081 (ast-branch)

# Python 2.5a0: 62091 (with)

# Python 2.5a0: 62092 (changed WITH_CLEANUP opcode)

# Python 2.5b3: 62101 (fix wrong code: for x, in ...)

# Python 2.5b3: 62111 (fix wrong code: x += yield)

# Python 2.5c1: 62121 (fix wrong lnotab with for loops and

# storing constants that should have been removed)

# Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp)

# Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode)

# Python 2.6a1: 62161 (WITH_CLEANUP optimization)

# Python 2.7a0: 62171 (optimize list comprehensions/change LIST_APPEND)

# Python 2.7a0: 62181 (optimize conditional branches:

# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE)

# Python 2.7a0 62191 (introduce SETUP_WITH)

# Python 2.7a0 62201 (introduce BUILD_SET)

# Python 2.7a0 62211 (introduce MAP_ADD and SET_ADD)

# Python 3000: 3000

# 3010 (removed UNARY_CONVERT)

# 3020 (added BUILD_SET)

# 3030 (added keyword-only parameters)

# 3040 (added signature annotations)

# 3050 (print becomes a function)

# 3060 (PEP 3115 metaclass syntax)

# 3061 (string literals become unicode)

# 3071 (PEP 3109 raise changes)

# 3081 (PEP 3137 make __file__ and __name__ unicode)

# 3091 (kill str8 interning)

# 3101 (merge from 2.6a0, see 62151)

# 3103 (__file__ points to source file)

# Python 3.0a4: 3111 (WITH_CLEANUP optimization).

# Python 3.0b1: 3131 (lexical exception stacking, including POP_EXCEPT

#3021)

# Python 3.1a1: 3141 (optimize list, set and dict comprehensions:

# change LIST_APPEND and SET_ADD, add MAP_ADD #2183)

# Python 3.1a1: 3151 (optimize conditional branches:

# introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE

#4715)

# Python 3.2a1: 3160 (add SETUP_WITH #6101)

# tag: cpython-32

# Python 3.2a2: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR #9225)

# tag: cpython-32

# Python 3.2a3 3180 (add DELETE_DEREF #4617)

# Python 3.3a1 3190 (__class__ super closure changed)

# Python 3.3a1 3200 (PEP 3155 __qualname__ added #13448)

# Python 3.3a1 3210 (added size modulo 2**32 to the pyc header #13645)

# Python 3.3a2 3220 (changed PEP 380 implementation #14230)

# Python 3.3a4 3230 (revert changes to implicit __class__ closure #14857)

# Python 3.4a1 3250 (evaluate positional default arguments before

# keyword-only defaults #16967)

# Python 3.4a1 3260 (add LOAD_CLASSDEREF; allow locals of class to override

# free vars #17853)

# Python 3.4a1 3270 (various tweaks to the __class__ closure #12370)

# Python 3.4a1 3280 (remove implicit class argument)

# Python 3.4a4 3290 (changes to __qualname__ computation #19301)

# Python 3.4a4 3300 (more changes to __qualname__ computation #19301)

# Python 3.4rc2 3310 (alter __qualname__ computation #20625)

# Python 3.5a1 3320 (PEP 465: Matrix multiplication operator #21176)

# Python 3.5b1 3330 (PEP 448: Additional Unpacking Generalizations #2292)

# Python 3.5b2 3340 (fix dictionary display evaluation order #11205)

# Python 3.5b3 3350 (add GET_YIELD_FROM_ITER opcode #24400)

# Python 3.5.2 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286)

# Python 3.6a0 3360 (add FORMAT_VALUE opcode #25483)

# Python 3.6a1 3361 (lineno delta of code.co_lnotab becomes signed #26107)

# Python 3.6a2 3370 (16 bit wordcode #26647)

# Python 3.6a2 3371 (add BUILD_CONST_KEY_MAP opcode #27140)

# Python 3.6a2 3372 (MAKE_FUNCTION simplification, remove MAKE_CLOSURE

# #27095)

# Python 3.6b1 3373 (add BUILD_STRING opcode #27078)

# Python 3.6b1 3375 (add SETUP_ANNOTATIONS and STORE_ANNOTATION opcodes

# #27985)

# Python 3.6b1 3376 (simplify CALL_FUNCTIONs & BUILD_MAP_UNPACK_WITH_CALL

#27213)

# Python 3.6b1 3377 (set __class__ cell from type.__new__ #23722)

# Python 3.6b2 3378 (add BUILD_TUPLE_UNPACK_WITH_CALL #28257)

# Python 3.6rc1 3379 (more thorough __class__ validation #23722)

# Python 3.7a1 3390 (add LOAD_METHOD and CALL_METHOD opcodes #26110)

# Python 3.7a2 3391 (update GET_AITER #31709)

# Python 3.7a4 3392 (PEP 552: Deterministic pycs #31650)

# Python 3.7b1 3393 (remove STORE_ANNOTATION opcode #32550)

# Python 3.7b5 3394 (restored docstring as the first stmt in the body;

# this might affected the first line number #32911)

# Python 3.8a1 3400 (move frame block handling to compiler #17611)

# Python 3.8a1 3401 (add END_ASYNC_FOR #33041)

# Python 3.8a1 3410 (PEP570 Python Positional-Only Parameters #36540)

# Python 3.8b2 3411 (Reverse evaluation order of key: value in dict

# comprehensions #35224)

# Python 3.8b2 3412 (Swap the position of positional args and positional

# only args in ast.arguments #37593)

# Python 3.8b4 3413 (Fix "break" and "continue" in "finally" #37830)

# Python 3.9a0 3420 (add LOAD_ASSERTION_ERROR #34880)

# Python 3.9a0 3421 (simplified bytecode for with blocks #32949)

# Python 3.9a0 3422 (remove BEGIN_FINALLY, END_FINALLY, CALL_FINALLY, POP_FINALLY bytecodes #33387)

# Python 3.9a2 3423 (add IS_OP, CONTAINS_OP and JUMP_IF_NOT_EXC_MATCH bytecodes #39156)

# Python 3.9a2 3424 (simplify bytecodes for *value unpacking)

# Python 3.9a2 3425 (simplify bytecodes for **value unpacking)

# Python 3.10a1 3430 (Make 'annotations' future by default)

# Python 3.10a1 3431 (New line number table format -- PEP 626)

# Python 3.10a2 3432 (Function annotation for MAKE_FUNCTION is changed from dict to tuple bpo-42202)

# Python 3.10a2 3433 (RERAISE restores f_lasti if oparg != 0)

# Python 3.10a6 3434 (PEP 634: Structural Pattern Matching)

# Python 3.10a7 3435 Use instruction offsets (as opposed to byte offsets).

# Python 3.10b1 3436 (Add GEN_START bytecode #43683)

# Python 3.10b1 3437 (Undo making 'annotations' future by default - We like to dance among core devs!)

# Python 3.10b1 3438 Safer line number table handling.

# Python 3.10b1 3439 (Add ROT_N)

# Python 3.11a1 3450 Use exception table for unwinding ("zero cost" exception handling)

# Python 3.11a1 3451 (Add CALL_METHOD_KW)

# Python 3.11a1 3452 (drop nlocals from marshaled code objects)

# Python 3.11a1 3453 (add co_fastlocalnames and co_fastlocalkinds)

# Python 3.11a1 3454 (compute cell offsets relative to locals bpo-43693)

# Python 3.11a1 3455 (add MAKE_CELL bpo-43693)

# Python 3.11a1 3456 (interleave cell args bpo-43693)

# Python 3.11a1 3457 (Change localsplus to a bytes object bpo-43693)

# Python 3.11a1 3458 (imported objects now don't use LOAD_METHOD/CALL_METHOD)

# Python 3.11a1 3459 (PEP 657: add end line numbers and column offsets for instructions)

# Python 3.11a1 3460 (Add co_qualname field to PyCodeObject bpo-44530)

# Python 3.11a1 3461 (JUMP_ABSOLUTE must jump backwards)

# Python 3.11a2 3462 (bpo-44511: remove COPY_DICT_WITHOUT_KEYS, change

# MATCH_CLASS and MATCH_KEYS, and add COPY)

# Python 3.11a3 3463 (bpo-45711: JUMP_IF_NOT_EXC_MATCH no longer pops the

# active exception)

# Python 3.11a3 3464 (bpo-45636: Merge numeric BINARY_*/INPLACE_* into

# BINARY_OP)

# Python 3.11a3 3465 (Add COPY_FREE_VARS opcode)

# Python 3.11a4 3466 (bpo-45292: PEP-654 except*)

# Python 3.11a4 3467 (Change CALL_xxx opcodes)

# Python 3.11a4 3468 (Add SEND opcode)

# Python 3.11a4 3469 (bpo-45711: remove type, traceback from exc_info)

# Python 3.11a4 3470 (bpo-46221: PREP_RERAISE_STAR no longer pushes lasti)

# Python 3.11a4 3471 (bpo-46202: remove pop POP_EXCEPT_AND_RERAISE)

# Python 3.11a4 3472 (bpo-46009: replace GEN_START with POP_TOP)

# Python 3.11a4 3473 (Add POP_JUMP_IF_NOT_NONE/POP_JUMP_IF_NONE opcodes)

# Python 3.11a4 3474 (Add RESUME opcode)

# Python 3.11a5 3475 (Add RETURN_GENERATOR opcode)

# Python 3.11a5 3476 (Add ASYNC_GEN_WRAP opcode)

# Python 3.11a5 3477 (Replace DUP_TOP/DUP_TOP_TWO with COPY and

# ROT_TWO/ROT_THREE/ROT_FOUR/ROT_N with SWAP)

# Python 3.11a5 3478 (New CALL opcodes)

# Python 3.11a5 3479 (Add PUSH_NULL opcode)

# Python 3.11a5 3480 (New CALL opcodes, second iteration)

# Python 3.11a5 3481 (Use inline cache for BINARY_OP)

# Python 3.11a5 3482 (Use inline caching for UNPACK_SEQUENCE and LOAD_GLOBAL)

# Python 3.11a5 3483 (Use inline caching for COMPARE_OP and BINARY_SUBSCR)

# Python 3.11a5 3484 (Use inline caching for LOAD_ATTR, LOAD_METHOD, and

# STORE_ATTR)

# Python 3.11a5 3485 (Add an oparg to GET_AWAITABLE)

# Python 3.11a6 3486 (Use inline caching for PRECALL and CALL)

# Python 3.11a6 3487 (Remove the adaptive "oparg counter" mechanism)

# Python 3.11a6 3488 (LOAD_GLOBAL can push additional NULL)

# Python 3.11a6 3489 (Add JUMP_BACKWARD, remove JUMP_ABSOLUTE)

# Python 3.11a6 3490 (remove JUMP_IF_NOT_EXC_MATCH, add CHECK_EXC_MATCH)

# Python 3.11a6 3491 (remove JUMP_IF_NOT_EG_MATCH, add CHECK_EG_MATCH,

# add JUMP_BACKWARD_NO_INTERRUPT, make JUMP_NO_INTERRUPT virtual)

# Python 3.11a7 3492 (make POP_JUMP_IF_NONE/NOT_NONE/TRUE/FALSE relative)

# Python 3.11a7 3493 (Make JUMP_IF_TRUE_OR_POP/JUMP_IF_FALSE_OR_POP relative)

# Python 3.11a7 3494 (New location info table)

# Python 3.11b4 3495 (Set line number of module's RESUME instr to 0 per PEP 626)

# Python 3.12a1 3500 (Remove PRECALL opcode)

# Python 3.12a1 3501 (YIELD_VALUE oparg == stack_depth)

# Python 3.12a1 3502 (LOAD_FAST_CHECK, no NULL-check in LOAD_FAST)

# Python 3.12a1 3503 (Shrink LOAD_METHOD cache)

# Python 3.12a1 3504 (Merge LOAD_METHOD back into LOAD_ATTR)

# Python 3.12a1 3505 (Specialization/Cache for FOR_ITER)

# Python 3.12a1 3506 (Add BINARY_SLICE and STORE_SLICE instructions)

# Python 3.12a1 3507 (Set lineno of module's RESUME to 0)

# Python 3.12a1 3508 (Add CLEANUP_THROW)

# Python 3.12a1 3509 (Conditional jumps only jump forward)

# Python 3.12a2 3510 (FOR_ITER leaves iterator on the stack)

# Python 3.12a2 3511 (Add STOPITERATION_ERROR instruction)

# Python 3.12a2 3512 (Remove all unused consts from code objects)

# Python 3.12a4 3513 (Add CALL_INTRINSIC_1 instruction, removed STOPITERATION_ERROR, PRINT_EXPR, IMPORT_STAR)

# Python 3.12a4 3514 (Remove ASYNC_GEN_WRAP, LIST_TO_TUPLE, and UNARY_POSITIVE)

# Python 3.12a5 3515 (Embed jump mask in COMPARE_OP oparg)

# Python 3.12a5 3516 (Add COMPARE_AND_BRANCH instruction)

# Python 3.12a5 3517 (Change YIELD_VALUE oparg to exception block depth)

# Python 3.12a6 3518 (Add RETURN_CONST instruction)

# Python 3.12a6 3519 (Modify SEND instruction)

# Python 3.12a6 3520 (Remove PREP_RERAISE_STAR, add CALL_INTRINSIC_2)

# Python 3.12a7 3521 (Shrink the LOAD_GLOBAL caches)

# Python 3.12a7 3522 (Removed JUMP_IF_FALSE_OR_POP/JUMP_IF_TRUE_OR_POP)

# Python 3.12a7 3523 (Convert COMPARE_AND_BRANCH back to COMPARE_OP)

# Python 3.12a7 3524 (Shrink the BINARY_SUBSCR caches)

# Python 3.12b1 3525 (Shrink the CALL caches)

# Python 3.12b1 3526 (Add instrumentation support)

# Python 3.12b1 3527 (Add LOAD_SUPER_ATTR)

# Python 3.12b1 3528 (Add LOAD_SUPER_ATTR_METHOD specialization)

# Python 3.12b1 3529 (Inline list/dict/set comprehensions)

# Python 3.12b1 3530 (Shrink the LOAD_SUPER_ATTR caches)

# Python 3.12b1 3531 (Add PEP 695 changes)

# Python 3.13 will start with 3550

# Please don't copy-paste the same pre-release tag for new entries above!!!

# You should always use the *upcoming* tag. For example, if 3.12a6 came out

# a week ago, I should put "Python 3.12a7" next to my new magic number.

# MAGIC must change whenever the bytecode emitted by the compiler may no

# longer be understood by older implementations of the eval loop (usually

# due to the addition of new opcodes).

#

# Starting with Python 3.11, Python 3.n starts with magic number 2900+50n.

#

# Whenever MAGIC_NUMBER is changed, the ranges in the magic_values array

# in PC/launcher.c must also be updated.

MAGIC_NUMBER = (3531).to_bytes(2, 'little') + b'\r\n'

_RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c

_PYCACHE = '__pycache__'

_OPT = 'opt-'

SOURCE_SUFFIXES = ['.py']

if _MS_WINDOWS:

SOURCE_SUFFIXES.append('.pyw')

EXTENSION_SUFFIXES = _imp.extension_suffixes()

BYTECODE_SUFFIXES = ['.pyc']

# Deprecated.

DEBUG_BYTECODE_SUFFIXES = OPTIMIZED_BYTECODE_SUFFIXES = BYTECODE_SUFFIXES

def cache_from_source(path, debug_override=None, *, optimization=None):

"""Given the path to a .py file, return the path to its .pyc file.

The .py file does not need to exist; this simply returns the path to the

.pyc file calculated as if the .py file were imported.

The 'optimization' parameter controls the presumed optimization level of

the bytecode file. If 'optimization' is not None, the string representation

of the argument is taken and verified to be alphanumeric (else ValueError

is raised).

The debug_override parameter is deprecated. If debug_override is not None,

a True value is the same as setting 'optimization' to the empty string

while a False value is equivalent to setting 'optimization' to '1'.

If sys.implementation.cache_tag is None then NotImplementedError is raised.

"""

if debug_override is not None:

_warnings.warn('the debug_override parameter is deprecated; use '

"'optimization' instead", DeprecationWarning)

if optimization is not None:

message = 'debug_override or optimization must be set to None'

raise TypeError(message)

optimization = '' if debug_override else 1

path = _os.fspath(path)

head, tail = _path_split(path)

base, sep, rest = tail.rpartition('.')

tag = sys.implementation.cache_tag

if tag is None:

raise NotImplementedError('sys.implementation.cache_tag is None')

almost_filename = ''.join([(base if base else rest), sep, tag])

if optimization is None:

if sys.flags.optimize == 0:

optimization = ''

else:

optimization = sys.flags.optimize

optimization = str(optimization)

if optimization != '':

if not optimization.isalnum():

raise ValueError(f'{optimization!r} is not alphanumeric')

almost_filename = f'{almost_filename}.{_OPT}{optimization}'

filename = almost_filename + BYTECODE_SUFFIXES[0]

if sys.pycache_prefix is not None:

# We need an absolute path to the py file to avoid the possibility of

# collisions within sys.pycache_prefix, if someone has two different

# `foo/bar.py` on their system and they import both of them using the

# same sys.pycache_prefix. Let's say sys.pycache_prefix is

# `C:\Bytecode`; the idea here is that if we get `Foo\Bar`, we first

# make it absolute (`C:\Somewhere\Foo\Bar`), then make it root-relative

# (`Somewhere\Foo\Bar`), so we end up placing the bytecode file in an

# unambiguous `C:\Bytecode\Somewhere\Foo\Bar\`.

head = _path_abspath(head)

# Strip initial drive from a Windows path. We know we have an absolute

# path here, so the second part of the check rules out a POSIX path that

# happens to contain a colon at the second character.

if head[1] == ':' and head[0] not in path_separators:

head = head[2:]

# Strip initial path separator from `head` to complete the conversion

# back to a root-relative path before joining.

return _path_join(

sys.pycache_prefix,

head.lstrip(path_separators),

filename,

)

return _path_join(head, _PYCACHE, filename)

def source_from_cache(path):

"""Given the path to a .pyc. file, return the path to its .py file.

The .pyc file does not need to exist; this simply returns the path to

the .py file calculated to correspond to the .pyc file. If path does

not conform to PEP 3147/488 format, ValueError will be raised. If

sys.implementation.cache_tag is None then NotImplementedError is raised.

"""

if sys.implementation.cache_tag is None:

raise NotImplementedError('sys.implementation.cache_tag is None')

path = _os.fspath(path)

head, pycache_filename = _path_split(path)

found_in_pycache_prefix = False

if sys.pycache_prefix is not None:

stripped_path = sys.pycache_prefix.rstrip(path_separators)

if head.startswith(stripped_path + path_sep):

head = head[len(stripped_path):]

found_in_pycache_prefix = True

if not found_in_pycache_prefix:

head, pycache = _path_split(head)

if pycache != _PYCACHE:

raise ValueError(f'{_PYCACHE} not bottom-level directory in '

f'{path!r}')

dot_count = pycache_filename.count('.')

if dot_count not in {2, 3}:

raise ValueError(f'expected only 2 or 3 dots in {pycache_filename!r}')

elif dot_count == 3:

optimization = pycache_filename.rsplit('.', 2)[-2]

if not optimization.startswith(_OPT):

raise ValueError("optimization portion of filename does not start "

f"with {_OPT!r}")

opt_level = optimization[len(_OPT):]

if not opt_level.isalnum():

raise ValueError(f"optimization level {optimization!r} is not an "

"alphanumeric value")

base_filename = pycache_filename.partition('.')[0]

return _path_join(head, base_filename + SOURCE_SUFFIXES[0])

def _get_sourcefile(bytecode_path):

"""Convert a bytecode file path to a source path (if possible).

This function exists purely for backwards-compatibility for

PyImport_ExecCodeModuleWithFilenames() in the C API.

"""

if len(bytecode_path) == 0:

return None

rest, _, extension = bytecode_path.rpartition('.')

if not rest or extension.lower()[-3:-1] != 'py':

return bytecode_path

try:

source_path = source_from_cache(bytecode_path)

except (NotImplementedError, ValueError):

source_path = bytecode_path[:-1]

return source_path if _path_isfile(source_path) else bytecode_path

def _get_cached(filename):

if filename.endswith(tuple(SOURCE_SUFFIXES)):

try:

return cache_from_source(filename)

except NotImplementedError:

pass

elif filename.endswith(tuple(BYTECODE_SUFFIXES)):

return filename

else:

return None

def _calc_mode(path):

"""Calculate the mode permissions for a bytecode file."""

try:

mode = _path_stat(path).st_mode

except OSError:

mode = 0o666

# We always ensure write access so we can update cached files

# later even when the source files are read-only on Windows (#6074)

mode |= 0o200

return mode

def _check_name(method):

"""Decorator to verify that the module being requested matches the one the

loader can handle.

The first argument (self) must define _name which the second argument is

compared against. If the comparison fails then ImportError is raised.

"""

def _check_name_wrapper(self, name=None, *args, **kwargs):

if name is None:

name = self.name

elif self.name != name:

raise ImportError('loader for %s cannot handle %s' %

(self.name, name), name=name)

return method(self, name, *args, **kwargs)

# FIXME: @_check_name is used to define class methods before the

# _bootstrap module is set by _set_bootstrap_module().

if _bootstrap is not None:

_wrap = _bootstrap._wrap

else:

def _wrap(new, old):

for replace in ['__module__', '__name__', '__qualname__', '__doc__']:

if hasattr(old, replace):

setattr(new, replace, getattr(old, replace))

new.__dict__.update(old.__dict__)

_wrap(_check_name_wrapper, method)

return _check_name_wrapper

def _classify_pyc(data, name, exc_details):

"""Perform basic validity checking of a pyc header and return the flags field,

which determines how the pyc should be further validated against the source.

*data* is the contents of the pyc file. (Only the first 16 bytes are

required, though.)

*name* is the name of the module being imported. It is used for logging.

*exc_details* is a dictionary passed to ImportError if it raised for

improved debugging.

ImportError is raised when the magic number is incorrect or when the flags

field is invalid. EOFError is raised when the data is found to be truncated.

"""

magic = data[:4]

if magic != MAGIC_NUMBER:

message = f'bad magic number in {name!r}: {magic!r}'

_bootstrap._verbose_message('{}', message)

raise ImportError(message, **exc_details)

if len(data) < 16:

message = f'reached EOF while reading pyc header of {name!r}'

_bootstrap._verbose_message('{}', message)

raise EOFError(message)

flags = _unpack_uint32(data[4:8])

# Only the first two flags are defined.

if flags & ~0b11:

message = f'invalid flags {flags!r} in {name!r}'

raise ImportError(message, **exc_details)

return flags

def _validate_timestamp_pyc(data, source_mtime, source_size, name,

exc_details):

"""Validate a pyc against the source last-modified time.

*data* is the contents of the pyc file. (Only the first 16 bytes are

required.)

*source_mtime* is the last modified timestamp of the source file.

*source_size* is None or the size of the source file in bytes.

*name* is the name of the module being imported. It is used for logging.

*exc_details* is a dictionary passed to ImportError if it raised for

improved debugging.

An ImportError is raised if the bytecode is stale.

"""

if _unpack_uint32(data[8:12]) != (source_mtime & 0xFFFFFFFF):

message = f'bytecode is stale for {name!r}'

_bootstrap._verbose_message('{}', message)

raise ImportError(message, **exc_details)

if (source_size is not None and

_unpack_uint32(data[12:16]) != (source_size & 0xFFFFFFFF)):

raise ImportError(f'bytecode is stale for {name!r}', **exc_details)

def _validate_hash_pyc(data, source_hash, name, exc_details):

"""Validate a hash-based pyc by checking the real source hash against the one in

the pyc header.

*data* is the contents of the pyc file. (Only the first 16 bytes are

required.)

*source_hash* is the importlib.util.source_hash() of the source file.

*name* is the name of the module being imported. It is used for logging.

*exc_details* is a dictionary passed to ImportError if it raised for

improved debugging.

An ImportError is raised if the bytecode is stale.

"""

if data[8:16] != source_hash:

raise ImportError(

f'hash in bytecode doesn\'t match hash of source {name!r}',

**exc_details,

)

def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None):

"""Compile bytecode as found in a pyc."""

code = marshal.loads(data)

if isinstance(code, _code_type):

_bootstrap._verbose_message('code object from {!r}', bytecode_path)

if source_path is not None:

_imp._fix_co_filename(code, source_path)

return code

else:

raise ImportError(f'Non-code object in {bytecode_path!r}',

name=name, path=bytecode_path)

def _code_to_timestamp_pyc(code, mtime=0, source_size=0):

"Produce the data for a timestamp-based pyc."

data = bytearray(MAGIC_NUMBER)

data.extend(_pack_uint32(0))

data.extend(_pack_uint32(mtime))

data.extend(_pack_uint32(source_size))

data.extend(marshal.dumps(code))

return data

def _code_to_hash_pyc(code, source_hash, checked=True):

"Produce the data for a hash-based pyc."

data = bytearray(MAGIC_NUMBER)

flags = 0b1 | checked << 1

data.extend(_pack_uint32(flags))

assert len(source_hash) == 8

data.extend(source_hash)

data.extend(marshal.dumps(code))

return data

def decode_source(source_bytes):

"""Decode bytes representing source code and return the string.

Universal newline support is used in the decoding.

"""

import tokenize # To avoid bootstrap issues.

source_bytes_readline = _io.BytesIO(source_bytes).readline

encoding = tokenize.detect_encoding(source_bytes_readline)

newline_decoder = _io.IncrementalNewlineDecoder(None, True)

return newline_decoder.decode(source_bytes.decode(encoding[0]))

# Module specifications #######################################################

_POPULATE = object()

def spec_from_file_location(name, location=None, *, loader=None,

submodule_search_locations=_POPULATE):

"""Return a module spec based on a file location.

To indicate that the module is a package, set

submodule_search_locations to a list of directory paths. An

empty list is sufficient, though its not otherwise useful to the

import system.

The loader must take a spec as its only __init__() arg.

"""

if location is None:

# The caller may simply want a partially populated location-

# oriented spec. So we set the location to a bogus value and

# fill in as much as we can.

location = '<unknown>'

if hasattr(loader, 'get_filename'):

# ExecutionLoader

try:

location = loader.get_filename(name)

except ImportError:

pass

else:

location = _os.fspath(location)

try:

location = _path_abspath(location)

except OSError:

pass

# If the location is on the filesystem, but doesn't actually exist,

# we could return None here, indicating that the location is not

# valid. However, we don't have a good way of testing since an

# indirect location (e.g. a zip file or URL) will look like a

# non-existent file relative to the filesystem.

spec = _bootstrap.ModuleSpec(name, loader, origin=location)

spec._set_fileattr = True

# Pick a loader if one wasn't provided.

if loader is None:

for loader_class, suffixes in _get_supported_file_loaders():

if location.endswith(tuple(suffixes)):

loader = loader_class(name, location)

spec.loader = loader

break

else:

return None

# Set submodule_search_paths appropriately.

if submodule_search_locations is _POPULATE:

# Check the loader.

if hasattr(loader, 'is_package'):

try:

is_package = loader.is_package(name)

except ImportError:

pass

else:

if is_package:

spec.submodule_search_locations = []

else:

spec.submodule_search_locations = submodule_search_locations

if spec.submodule_search_locations == []:

if location:

dirname = _path_split(location)[0]

spec.submodule_search_locations.append(dirname)

return spec

def _bless_my_loader(module_globals):

"""Helper function for _warnings.c

See GH#97850 for details.

"""

# 2022-10-06(warsaw): For now, this helper is only used in _warnings.c and

# that use case only has the module globals. This function could be

# extended to accept either that or a module object. However, in the

# latter case, it would be better to raise certain exceptions when looking

# at a module, which should have either a __loader__ or __spec__.loader.

# For backward compatibility, it is possible that we'll get an empty

# dictionary for the module globals, and that cannot raise an exception.

if not isinstance(module_globals, dict):

return None

missing = object()

loader = module_globals.get('__loader__', None)

spec = module_globals.get('__spec__', missing)

if loader is None:

if spec is missing:

# If working with a module:

# raise AttributeError('Module globals is missing a __spec__')

return None

elif spec is None:

raise ValueError('Module globals is missing a __spec__.loader')

spec_loader = getattr(spec, 'loader', missing)

if spec_loader in (missing, None):

if loader is None:

exc = AttributeError if spec_loader is missing else ValueError

raise exc('Module globals is missing a __spec__.loader')

_warnings.warn(

'Module globals is missing a __spec__.loader',

DeprecationWarning)

spec_loader = loader

assert spec_loader is not None

if loader is not None and loader != spec_loader:

_warnings.warn(

'Module globals; __loader__ != __spec__.loader',

DeprecationWarning)

return loader

return spec_loader

# Loaders #####################################################################

class WindowsRegistryFinder:

"""Meta path finder for modules declared in the Windows registry."""

REGISTRY_KEY = (

'Software\\Python\\PythonCore\\{sys_version}'

'\\Modules\\{fullname}')

REGISTRY_KEY_DEBUG = (

'Software\\Python\\PythonCore\\{sys_version}'

'\\Modules\\{fullname}\\Debug')

DEBUG_BUILD = (_MS_WINDOWS and '_d.pyd' in EXTENSION_SUFFIXES)

@staticmethod

def _open_registry(key):

try:

return winreg.OpenKey(winreg.HKEY_CURRENT_USER, key)

except OSError:

return winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, key)

@classmethod

def _search_registry(cls, fullname):

if cls.DEBUG_BUILD:

registry_key = cls.REGISTRY_KEY_DEBUG

else:

registry_key = cls.REGISTRY_KEY

key = registry_key.format(fullname=fullname,

sys_version='%d.%d' % sys.version_info[:2])

try:

with cls._open_registry(key) as hkey:

filepath = winreg.QueryValue(hkey, '')

except OSError:

return None

return filepath

@classmethod

def find_spec(cls, fullname, path=None, target=None):

filepath = cls._search_registry(fullname)

if filepath is None:

return None

try:

_path_stat(filepath)

except OSError:

return None

for loader, suffixes in _get_supported_file_loaders():

if filepath.endswith(tuple(suffixes)):

spec = _bootstrap.spec_from_loader(fullname,

loader(fullname, filepath),

origin=filepath)

return spec

class _LoaderBasics:

"""Base class of common code needed by both SourceLoader and

SourcelessFileLoader."""

def is_package(self, fullname):

"""Concrete implementation of InspectLoader.is_package by checking if

the path returned by get_filename has a filename of '__init__.py'."""

filename = _path_split(self.get_filename(fullname))[1]

filename_base = filename.rsplit('.', 1)[0]

tail_name = fullname.rpartition('.')[2]

return filename_base == '__init__' and tail_name != '__init__'

def create_module(self, spec):

"""Use default semantics for module creation."""

def exec_module(self, module):

"""Execute the module."""

code = self.get_code(module.__name__)

if code is None:

raise ImportError(f'cannot load module {module.__name__!r} when '

'get_code() returns None')

_bootstrap._call_with_frames_removed(exec, code, module.__dict__)