How to import a module given its name as string?

Question

I\'m writing a Python application that takes as a command as an argument, for example:

$ python myapp.py command1

I want the application to

Answer 1

Note: imp is deprecated since Python 3.4 in favor of importlib

As mentioned the imp module provides you loading functions:

imp.load_source(name, path)
imp.load_compiled(name, path)

I've used these before to perform something similar.

In my case I defined a specific class with defined methods that were required. Once I loaded the module I would check if the class was in the module, and then create an instance of that class, something like this:

import imp
import os

def load_from_file(filepath):
    class_inst = None
    expected_class = 'MyClass'

    mod_name,file_ext = os.path.splitext(os.path.split(filepath)[-1])

    if file_ext.lower() == '.py':
        py_mod = imp.load_source(mod_name, filepath)

    elif file_ext.lower() == '.pyc':
        py_mod = imp.load_compiled(mod_name, filepath)

    if hasattr(py_mod, expected_class):
        class_inst = getattr(py_mod, expected_class)()

    return class_inst