Question

Given the source code of a Python file, I would like to detect all imported objects. For example, given this source:

import mymod
from mymod2 import obj1, obj2, obj3
from mymod3 import aobj

I want to get:

[('mymod2', 'obj1', 'obj2', 'obj3'), ('mymod3', 'aobj')]

I have already tried this regex:

r'from (?P<mod>[_\w\d]+) import (?:(?P<obj>[_\w\d]+)[,\s]?)+'

But I only get the first imported object:

[('mymod2', 'obj1'), ('mymod3', 'aobj')]

Answer 1

A better tool than regular expressions is the ast module that comes with Python. To find all from ... import statements in the outermost scope of a.py and print all imported names, you could use

import ast
code = open("a.py").read()
for node in ast.parse(code).body:
    if isinstance(node, ast.ImportFrom):
        for name in node.names:
            print name.name

Note that this simple code will miss any statements that are not directly at module level, such as import statements inside a try-block. This can easily be fixed by using ast.walk() to walk over all nodes.