Python: How to import a package twice?

Question

Is there a way to import a package twice into the same python session under the same name, but in different areas, in a multi-threaded environment?

I would like to import a package and then redefine some of its functions so that it changes its behavior only when used in a specific class.

For example, is it possible to achieve something similar?

import mod

class MyClass:

  mod = __import__('mod')

  def __init__():
     mod.function = new_function # override module function

  def method():
     mod.function() # call new_function

mod.function() # call original function

This may seem strange, but in this case, the user receiving the class will not have to change their code in order to use the improved package.

Answer 1

It looks like a job for the context manager.

import modul

def newfunc():
    print('newfunc')

class MyClass:
    def __enter__(self):
        self._f = modul.func
        modul.func = newfunc
        return self

    def __exit__(self, type, value, tb):
        modul.func = self._f

    def method(self):
        modul.func()


modul.func()
with MyClass() as obj:
    obj.method()
    modul.func()
modul.func()

exits

func
newfunc
newfunc
func

where modul.pycontains

def func():
    print('func')

. ( OP)

Answer 2

:

def freshimport(name):
    import sys, importlib
    if name in sys.modules:
        del sys.modules[name]
    mod = importlib.import_module(name)
    sys.modules[name] = mod
    return mod

:

import mymodule as m1
m2 = freshimport('mymodule')
assert m1.func is not m2.func

importlib.reload , "" :

import importlib
import mymodule as m1
print(id(m1.func))
m2 = importlib.reload(m1)
print(id(m1.func))
print(id(m2.func))

:

139681606300944
139681606050680
139681606050680