sys.modules - Listing Loaded Modules

Python Tutorials - Herong's Tutorial Examples

∟sys.modules - Listing Loaded Modules

This section provides a tutorial example on how to list modules already loaded in the memory cache, using the 'sys.modules' attribute.

If you want to know how many modules have already been loaded in the memory cache, you can use the "sys.modules" attribute, which is a "dict" object holding a name-description pair for each loaded module.

The code below shows you an example of listing loaded modules.

# import a module from a module file
>>> import module_test

# list all loaded modules
>>> import sys
>>> for m in sys.modules:
...    print(f"name, description = {m}, {sys.modules[m]}")
...
name, description = builtins, <module 'builtins' (built-in)>
name, description = _io, <module 'io' (built-in)>
name, description = time, <module 'time' (built-in)>
name, description = zipimport, <module 'zipimport' (frozen)>
name, description = __main__, <module '__main__' (built-in)>
name, description = io, <module 'io' from
                    '/usr/lib/python3.8/io.py'>
name, description = google, <module 'google' (namespace)>
...
name, description = module_test, <module 'module_test' from
                    '/home/herong/module_test.py'>
name, description = sys, <module 'sys' (built-in)>