Is there a standard way to list names of Python modules in a package?

Question

Using python2.3 and above, you could also use the pkgutil module:

>>> import pkgutil
>>> [name for _, name, _ in pkgutil.iter_modules(['testpkg'])]
['modulea', 'moduleb']

EDIT: Note that the parameter is not a list of modules, but a list of paths, so you might want to do something like this:

>>> import os.path, pkgutil
>>> import testpkg
>>> pkgpath = os.path.dirname(testpkg.__file__)
>>> print([name for _, name, _ in pkgutil.iter_modules([pkgpath])])

import module
help(module)

Maybe this will do what you're looking for?

import imp
import os
MODULE_EXTENSIONS = ('.py', '.pyc', '.pyo')

def package_contents(package_name):
    file, pathname, description = imp.find_module(package_name)
    if file:
        raise ImportError('Not a package: %r', package_name)
    # Use a set because some may be both source and compiled.
    return set([os.path.splitext(module)[0]
        for module in os.listdir(pathname)
        if module.endswith(MODULE_EXTENSIONS)])

Don't know if I'm overlooking something, or if the answers are just out-dated but;

As stated by user815423426 this only works for live objects and the listed modules are only modules that were imported before.

Listing modules in a package seems really easy using inspect:

>>> import inspect, testpkg
>>> inspect.getmembers(testpkg, inspect.ismodule)
['modulea', 'moduleb']

This is a recursive version that works with python 3.6 and above:

import importlib.util
from pathlib import Path
import os
MODULE_EXTENSIONS = '.py'

def package_contents(package_name):
    spec = importlib.util.find_spec(package_name)
    if spec is None:
        return set()

    pathname = Path(spec.origin).parent
    ret = set()
    with os.scandir(pathname) as entries:
        for entry in entries:
            if entry.name.startswith('__'):
                continue
            current = '.'.join((package_name, entry.name.partition('.')[0]))
            if entry.is_file():
                if entry.name.endswith(MODULE_EXTENSIONS):
                    ret.add(current)
            elif entry.is_dir():
                ret.add(current)
                ret |= package_contents(current)


    return ret