mirror of
https://github.com/python/cpython.git
synced 2024-11-27 23:47:29 +01:00
139 lines
3.5 KiB
Python
139 lines
3.5 KiB
Python
"""A pure Python implementation of import.
|
|
|
|
References on import:
|
|
|
|
* Language reference
|
|
http://docs.python.org/ref/import.html
|
|
* __import__ function
|
|
http://docs.python.org/lib/built-in-funcs.html
|
|
* Packages
|
|
http://www.python.org/doc/essays/packages.html
|
|
* PEP 235: Import on Case-Insensitive Platforms
|
|
http://www.python.org/dev/peps/pep-0235
|
|
* PEP 275: Import Modules from Zip Archives
|
|
http://www.python.org/dev/peps/pep-0273
|
|
* PEP 302: New Import Hooks
|
|
http://www.python.org/dev/peps/pep-0302/
|
|
* PEP 328: Imports: Multi-line and Absolute/Relative
|
|
http://www.python.org/dev/peps/pep-0328
|
|
|
|
"""
|
|
from . import _bootstrap
|
|
|
|
# XXX Temporary functions that should eventually be removed.
|
|
import os
|
|
import re
|
|
import tokenize
|
|
|
|
def _set__import__():
|
|
"""Set __import__ to an instance of Import."""
|
|
global original__import__
|
|
original__import__ = __import__
|
|
__builtins__['__import__'] = Import()
|
|
|
|
|
|
def _reset__import__():
|
|
"""Set __import__ back to the original implementation (assumes
|
|
_set__import__ was called previously)."""
|
|
__builtins__['__import__'] = original__import__
|
|
|
|
|
|
def _case_ok(directory, check):
|
|
"""Check if the directory contains something matching 'check'.
|
|
|
|
No check is done if the file/directory exists or not.
|
|
|
|
"""
|
|
if 'PYTHONCASEOK' in os.environ:
|
|
return True
|
|
elif check in os.listdir(directory):
|
|
return True
|
|
return False
|
|
|
|
|
|
def _w_long(x):
|
|
"""Convert a 32-bit integer to little-endian.
|
|
|
|
XXX Temporary until marshal's long functions are exposed.
|
|
|
|
"""
|
|
x = int(x)
|
|
int_bytes = []
|
|
int_bytes.append(x & 0xFF)
|
|
int_bytes.append((x >> 8) & 0xFF)
|
|
int_bytes.append((x >> 16) & 0xFF)
|
|
int_bytes.append((x >> 24) & 0xFF)
|
|
return bytearray(int_bytes)
|
|
|
|
|
|
def _r_long(int_bytes):
|
|
"""Convert 4 bytes in little-endian to an integer.
|
|
|
|
XXX Temporary until marshal's long function are exposed.
|
|
|
|
"""
|
|
x = int_bytes[0]
|
|
x |= int_bytes[1] << 8
|
|
x |= int_bytes[2] << 16
|
|
x |= int_bytes[3] << 24
|
|
return x
|
|
|
|
|
|
# Required built-in modules.
|
|
try:
|
|
import posix as _os
|
|
except ImportError:
|
|
try:
|
|
import nt as _os
|
|
except ImportError:
|
|
try:
|
|
import os2 as _os
|
|
except ImportError:
|
|
raise ImportError('posix, nt, or os2 module required for importlib')
|
|
_bootstrap._os = _os
|
|
import imp, sys, marshal, errno, _fileio
|
|
_bootstrap.imp = imp
|
|
_bootstrap.sys = sys
|
|
_bootstrap.marshal = marshal
|
|
_bootstrap.errno = errno
|
|
_bootstrap._fileio = _fileio
|
|
import _warnings
|
|
_bootstrap._warnings = _warnings
|
|
|
|
|
|
from os import sep
|
|
# For os.path.join replacement; pull from Include/osdefs.h:SEP .
|
|
_bootstrap.path_sep = sep
|
|
|
|
_bootstrap._case_ok = _case_ok
|
|
marshal._w_long = _w_long
|
|
marshal._r_long = _r_long
|
|
|
|
|
|
__import__ = _bootstrap.Import().__call__
|
|
|
|
|
|
def import_module(name, package=None):
|
|
"""Import a module.
|
|
|
|
The 'package' argument is required when performing a relative import. It
|
|
specifies the package to use as the anchor point from which to resolve the
|
|
relative import to an absolute import.
|
|
|
|
"""
|
|
if name.startswith('.'):
|
|
if not package:
|
|
raise TypeError("relative imports require the 'package' argument")
|
|
level = 0
|
|
for character in name:
|
|
if character != '.':
|
|
break
|
|
level += 1
|
|
name = Import._resolve_name(name[level:], package, level)
|
|
__import__(name)
|
|
return sys.modules[name]
|
|
|
|
|
|
|
|
from ._bootstrap import *
|