How do I upload (reload) a Python module?

General Discussions
1

How do I upload (reload) a Python module?

I have a long-running Python server and would like to be able to upgrade a service without restarting the server. What’s the best way to do this?

If foo.py has changed:

unimport foo  <-- How do I do this?
import foo
myfoo = foo.Foo()

How can I achieve this using python reload module?

2

Hi Anusha,

You can achieve this using importlib.reload() method. Python 3.x provides importlib.reload() as the recommended way to reload a module.

Here’s how you can do it:

import importlib
import foo

# Reload the module
importlib.reload(foo)

# Use the updated module
myfoo = foo.Foo()

This will reload the module foo and apply any changes made to it.

3

In Python 2.x, the imp module provides the reload() function. This is not recommended for newer versions of Python (Python 3.x), but it will work in older versions.

import imp
import foo

# Reload the module
imp.reload(foo)

# Use the updated module
myfoo = foo.Foo()

Note: This method works in Python 2.x but is not available in Python 3.x, so it’s better to use importlib.reload() in modern Python.

4

You can manually remove the module from sys.modules, and then re-import it. This is useful if you want to clear the module’s cache before re-importing it:

import sys
import foo

# Remove the module from sys.modules
del sys.modules['foo']

This approach can be used if importlib.reload() is not an option or if you want a more manual process to reset the module.

# Re-import the module
import foo

# Use the updated module
myfoo = foo.Foo()