hub/venv/lib/python3.7/site-packages/IPython/utils/shimmodule.py

95 lines
2.8 KiB
Python

"""A shim module for deprecated imports
"""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import sys
import types
from importlib import import_module
from .importstring import import_item
class ShimWarning(Warning):
"""A warning to show when a module has moved, and a shim is in its place."""
class ShimImporter(object):
"""Import hook for a shim.
This ensures that submodule imports return the real target module,
not a clone that will confuse `is` and `isinstance` checks.
"""
def __init__(self, src, mirror):
self.src = src
self.mirror = mirror
def _mirror_name(self, fullname):
"""get the name of the mirrored module"""
return self.mirror + fullname[len(self.src):]
def find_module(self, fullname, path=None):
"""Return self if we should be used to import the module."""
if fullname.startswith(self.src + '.'):
mirror_name = self._mirror_name(fullname)
try:
mod = import_item(mirror_name)
except ImportError:
return
else:
if not isinstance(mod, types.ModuleType):
# not a module
return None
return self
def load_module(self, fullname):
"""Import the mirrored module, and insert it into sys.modules"""
mirror_name = self._mirror_name(fullname)
mod = import_item(mirror_name)
sys.modules[fullname] = mod
return mod
class ShimModule(types.ModuleType):
def __init__(self, *args, **kwargs):
self._mirror = kwargs.pop("mirror")
src = kwargs.pop("src", None)
if src:
kwargs['name'] = src.rsplit('.', 1)[-1]
super(ShimModule, self).__init__(*args, **kwargs)
# add import hook for descendent modules
if src:
sys.meta_path.append(
ShimImporter(src=src, mirror=self._mirror)
)
@property
def __path__(self):
return []
@property
def __spec__(self):
"""Don't produce __spec__ until requested"""
return import_module(self._mirror).__spec__
def __dir__(self):
return dir(import_module(self._mirror))
@property
def __all__(self):
"""Ensure __all__ is always defined"""
mod = import_module(self._mirror)
try:
return mod.__all__
except AttributeError:
return [name for name in dir(mod) if not name.startswith('_')]
def __getattr__(self, key):
# Use the equivalent of import_item(name), see below
name = "%s.%s" % (self._mirror, key)
try:
return import_item(name)
except ImportError:
raise AttributeError(key)