47 lines
1.5 KiB
Python
47 lines
1.5 KiB
Python
# Code copied from https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/util/lazy_loader.py
|
|
"""A LazyLoader class."""
|
|
|
|
from __future__ import absolute_import
|
|
from __future__ import division
|
|
from __future__ import print_function
|
|
|
|
import importlib
|
|
import types
|
|
|
|
|
|
class LazyLoader(types.ModuleType):
|
|
"""Lazily import a module, mainly to avoid pulling in large dependencies.
|
|
|
|
`contrib`, and `ffmpeg` are examples of modules that are large and not always
|
|
needed, and this allows them to only be loaded when they are used.
|
|
"""
|
|
|
|
# The lint error here is incorrect.
|
|
def __init__(
|
|
self, local_name, parent_module_globals, name
|
|
): # pylint: disable=super-on-old-class
|
|
self._local_name = local_name
|
|
self._parent_module_globals = parent_module_globals
|
|
|
|
super(LazyLoader, self).__init__(name)
|
|
|
|
def _load(self):
|
|
# Import the target module and insert it into the parent's namespace
|
|
module = importlib.import_module(self.__name__)
|
|
self._parent_module_globals[self._local_name] = module
|
|
|
|
# Update this object's dict so that if someone keeps a reference to the
|
|
# LazyLoader, lookups are efficient (__getattr__ is only called on lookups
|
|
# that fail).
|
|
self.__dict__.update(module.__dict__)
|
|
|
|
return module
|
|
|
|
def __getattr__(self, item):
|
|
module = self._load()
|
|
return getattr(module, item)
|
|
|
|
def __dir__(self):
|
|
module = self._load()
|
|
return dir(module)
|