编辑（答案 V2）
之前的解决方案仅用于获取重置信息，但不会更改所有引用（超过reload，但少于所需）。要实际设置所有引用，我必须进入垃圾收集器，并在那里重写引用。现在它就像一个魅力！
请注意，如果 GC 关闭，或者重新加载不受 GC 监控的数据，则此将不起作用。如果你不想搞乱 GC，原来的答案对你来说可能就足够了。
新代码：
import importlib
import inspect
import gc
from enum import EnumMeta
from weakref import ref
_readonly_attrs = {'__annotations__', '__call__', '__class__', '__closure__', '__code__', '__defaults__', '__delattr__',
'__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__func__', '__ge__', '__get__',
'__getattribute__', '__globals__', '__gt__', '__hash__', '__init__', '__init_subclass__',
'__kwdefaults__', '__le__', '__lt__', '__module__', '__name__', '__ne__', '__new__', '__qualname__',
'__reduce__', '__reduce_ex__', '__repr__', '__self__', '__setattr__', '__sizeof__', '__str__',
'__subclasshook__', '__weakref__', '__members__', '__mro__', '__itemsize__', '__isabstractmethod__',
'__basicsize__', '__base__'}
def reset_module(module, inner_modules_also=True):
"""
This function is a stronger form of importlib's `reload` function. What it does, is that aside from reloading a
module, it goes to the old instance of the module, and sets all the (not read-only) attributes, functions and classes
to be the reloaded-module's
:param module: The module to reload (module reference, not the name)
:param inner_modules_also: Whether to treat ths module as a package as well, and reload all the modules within it.
"""
# For the case when the module is actually a package
if inner_modules_also:
submods = {submod for _, submod in inspect.getmembers(module)
if (type(submod).__name__ == 'module') and (submod.__package__.startswith(module.__name__))}
for submod in submods:
reset_module(submod, True)
# First, log all the references before reloading (because some references may be changed by the reload operation).
module_tree = _get_tree_references_to_reset_recursively(module, module.__name__)
new_module = importlib.reload(module)
_reset_item_recursively(module, module_tree, new_module)
def _update_referrers(item, new_item):
refs = gc.get_referrers(item)
weak_ref_item = ref(item)
for coll in refs:
if type(coll) == dict:
enumerator = coll.keys()
elif type(coll) == list:
enumerator = range(len(coll))
else:
continue
for key in enumerator:
if weak_ref_item() is None:
# No refs are left in the GC
return
if coll[key] is weak_ref_item():
coll[key] = new_item
def _get_tree_references_to_reset_recursively(item, module_name, grayed_out_item_ids = None):
if grayed_out_item_ids is None:
grayed_out_item_ids = set()
item_tree = dict()
attr_names = set(dir(item)) - _readonly_attrs
for sub_item_name in attr_names:
sub_item = getattr(item, sub_item_name)
item_tree[sub_item_name] = [sub_item, None]
try:
# Will work for classes and functions defined in that module.
mod_name = sub_item.__module__
except AttributeError:
mod_name = None
# If this item was defined within this module, deep-reset
if (mod_name is None) or (mod_name != module_name) or (id(sub_item) in grayed_out_item_ids) \
or isinstance(sub_item, EnumMeta):
continue
grayed_out_item_ids.add(id(sub_item))
item_tree[sub_item_name][1] = \
_get_tree_references_to_reset_recursively(sub_item, module_name, grayed_out_item_ids)
return item_tree
def _reset_item_recursively(item, item_subtree, new_item):
# Set children first so we don't lose the current references.
if item_subtree is not None:
for sub_item_name, (sub_item, sub_item_tree) in item_subtree.items():
try:
new_sub_item = getattr(new_item, sub_item_name)
except AttributeError:
# The item doesn't exist in the reloaded module. Ignore.
continue
try:
# Set the item
_reset_item_recursively(sub_item, sub_item_tree, new_sub_item)
except Exception as ex:
pass
_update_referrers(item, new_item)
原答案
正如@bobince 的回答中所写，如果在另一个模块中已经对该模块的引用（特别是如果它是使用as 关键字如import numpy as np 导入的），则该实例不会被覆盖。
在应用需要配置模块的“干净”状态的测试时，这对我来说是一个很大的问题，因此我编写了一个名为 reset_module 的函数，它使用 importlib 的 reload 函数并递归覆盖所有声明的模块的属性。它已经用 Python 3.6 版本进行了测试。
import importlib
import inspect
from enum import EnumMeta
_readonly_attrs = {'__annotations__', '__call__', '__class__', '__closure__', '__code__', '__defaults__', '__delattr__',
'__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__func__', '__ge__', '__get__',
'__getattribute__', '__globals__', '__gt__', '__hash__', '__init__', '__init_subclass__',
'__kwdefaults__', '__le__', '__lt__', '__module__', '__name__', '__ne__', '__new__', '__qualname__',
'__reduce__', '__reduce_ex__', '__repr__', '__self__', '__setattr__', '__sizeof__', '__str__',
'__subclasshook__', '__weakref__', '__members__', '__mro__', '__itemsize__', '__isabstractmethod__',
'__basicsize__', '__base__'}
def reset_module(module, inner_modules_also=True):
"""
This function is a stronger form of importlib's `reload` function. What it does, is that aside from reloading a
module, it goes to the old instance of the module, and sets all the (not read-only) attributes, functions and classes
to be the reloaded-module's
:param module: The module to reload (module reference, not the name)
:param inner_modules_also: Whether to treat ths module as a package as well, and reload all the modules within it.
"""
new_module = importlib.reload(module)
reset_items = set()
# For the case when the module is actually a package
if inner_modules_also:
submods = {submod for _, submod in inspect.getmembers(module)
if (type(submod).__name__ == 'module') and (submod.__package__.startswith(module.__name__))}
for submod in submods:
reset_module(submod, True)
_reset_item_recursively(module, new_module, module.__name__, reset_items)
def _reset_item_recursively(item, new_item, module_name, reset_items=None):
if reset_items is None:
reset_items = set()
attr_names = set(dir(item)) - _readonly_attrs
for sitem_name in attr_names:
sitem = getattr(item, sitem_name)
new_sitem = getattr(new_item, sitem_name)
try:
# Set the item
setattr(item, sitem_name, new_sitem)
try:
# Will work for classes and functions defined in that module.
mod_name = sitem.__module__
except AttributeError:
mod_name = None
# If this item was defined within this module, deep-reset
if (mod_name is None) or (mod_name != module_name) or (id(sitem) in reset_items) \
or isinstance(sitem, EnumMeta): # Deal with enums
continue
reset_items.add(id(sitem))
_reset_item_recursively(sitem, new_sitem, module_name, reset_items)
except Exception as ex:
raise Exception(sitem_name) from ex
注意：小心使用！在非外围模块（例如，定义外部使用的类的模块）上使用这些可能会导致 Python 中的内部问题（例如酸洗/取消酸洗问题）。