"""A pure Python implementation of import."""

__all__ = ['__import__', 'import_module', 'invalidate_caches', 'reload']

# Bootstrap help #####################################################

# Until bootstrapping is complete, DO NOT import any modules that attempt

# to import importlib._bootstrap (directly or indirectly). Since this

# partially initialised package would be present in sys.modules, those

# modules would get an uninitialised copy of the source version, instead

# of a fully initialised version (either the frozen one or the one

# initialised below if the frozen one is not available).

import _imp # Just the builtin component, NOT the full Python module

import sys

try:

import _frozen_importlib as _bootstrap

except ImportError:

from . import _bootstrap

_bootstrap._setup(sys, _imp)

else:

# importlib._bootstrap is the built-in import, ensure we don't create

# a second copy of the module.

_bootstrap.__name__ = 'importlib._bootstrap'

_bootstrap.__package__ = 'importlib'

try:

_bootstrap.__file__ = __file__.replace('__init__.py', '_bootstrap.py')

except NameError:

# __file__ is not guaranteed to be defined, e.g. if this code gets

# frozen by a tool like cx_Freeze.

pass

sys.modules['importlib._bootstrap'] = _bootstrap

try:

import _frozen_importlib_external as _bootstrap_external

except ImportError:

from . import _bootstrap_external

_bootstrap_external._set_bootstrap_module(_bootstrap)

_bootstrap._bootstrap_external = _bootstrap_external

else:

_bootstrap_external.__name__ = 'importlib._bootstrap_external'

_bootstrap_external.__package__ = 'importlib'

try:

_bootstrap_external.__file__ = __file__.replace('__init__.py', '_bootstrap_external.py')

except NameError:

# __file__ is not guaranteed to be defined, e.g. if this code gets

# frozen by a tool like cx_Freeze.

pass

sys.modules['importlib._bootstrap_external'] = _bootstrap_external

# To simplify imports in test code

_pack_uint32 = _bootstrap_external._pack_uint32

_unpack_uint32 = _bootstrap_external._unpack_uint32

# Fully bootstrapped at this point, import whatever you like, circular

# dependencies and startup overhead minimisation permitting :)

# Public API #########################################################

from ._bootstrap import __import__

def invalidate_caches():

"""Call the invalidate_caches() method on all meta path finders stored in

sys.meta_path (where implemented)."""

for finder in sys.meta_path:

if hasattr(finder, 'invalidate_caches'):

finder.invalidate_caches()

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.

"""

level = 0

if name.startswith('.'):

if not package:

raise TypeError("the 'package' argument is required to perform a "

f"relative import for {name!r}")

for character in name:

if character != '.':

break

level += 1

return _bootstrap._gcd_import(name[level:], package, level)

_RELOADING = {}

def reload(module):

"""Reload the module and return it.

The module must have been successfully imported before.

"""

try:

name = module.__spec__.name

except AttributeError:

try:

name = module.__name__

except AttributeError:

raise TypeError("reload() argument must be a module") from None

if sys.modules.get(name) is not module:

raise ImportError(f"module {name} not in sys.modules", name=name)

if name in _RELOADING:

return _RELOADING[name]

_RELOADING[name] = module

try:

parent_name = name.rpartition('.')[0]

if parent_name:

try:

parent = sys.modules[parent_name]

except KeyError:

raise ImportError(f"parent {parent_name!r} not in sys.modules",

name=parent_name) from None

else:

pkgpath = parent.__path__

else:

pkgpath = None

target = module

spec = module.__spec__ = _bootstrap._find_spec(name, pkgpath, target)

if spec is None:

raise ModuleNotFoundError(f"spec not found for the module {name!r}", name=name)

_bootstrap._exec(spec, module)

# The module may have replaced itself in sys.modules!

return sys.modules[name]

finally:

try:

del _RELOADING[name]

except KeyError:

pass