Python - Find all modules in a package without importing the package

get_modules.py

#!/usr/bin/env python3
#
# Find all modules in a package without importing the package.
# Returns a list of module names.
# This will work for a package installed in `site-packages` or read from source.
#
# Requires Python 3.9+

import importlib.util
import os
import site


def get_modules(package_name):
    try:
        mod_paths = importlib.util.find_spec(package_name).submodule_search_locations
    except AttributeError:
        raise Exception("package not found")
    modules = [package_name]
    for mod_path in mod_paths:
        path = mod_path if "site-packages" in mod_path else package_name
        for dirpath, _, filenames in os.walk(path):
            for filename in filenames:
                if filename.endswith(".py") and not filename.startswith("__"):
                    module_name = (
                        os.path.join(dirpath, filename)
                        .removeprefix(site.getsitepackages()[0])
                        .removeprefix(os.sep)
                        .removesuffix(".py")
                        .replace(os.sep, ".")
                    )
                    modules.append(module_name)
    return sorted(set(modules))


if __name__ == "__main__":
    # example usage:
    modules = get_modules("requests")
    for module in modules:
        print(module)