Can someone please make it more pythonic or better?

[Oltmans]

Greetings Python superstars,

I've a directory structure like following

tests /
	__init__.py
	testfile.py

testfile.py contains following code

import unittest

class Calculator(unittest.TestCase):
    def test_add(self):
        print 'just add'
    def test_divide(self):
        print 'diviide'
    def test_multiply(self):
        print 'mul'


class Car(unittest.TestCase):
    def test_start(self):
        print 'start'
    def test_move_right(self):
        print 'move right'
    def test_move_left(self):
        print 'move left'
    def test_stop(self):
        print 'stop'


Now give the following user-input I want to get all test-names.
user-input = tests.testfile (get all test-names from all
unittest.TestCase derived classes in test.testfile)
user-input = tests.testfile.Car (get all test-names from the Car
class)
user-input = tests.testfile.Cacr.test_stop

and I'm doing it this the following way and I really think there has
to be more readable, more pythonic and more possibly short way to do
it

import unittest
import sys
import inspect

def get_test_names(full_name,module):
    name = full_name.split('.')
    loader = unittest.TestLoader()
    if len(name) == 4:
        return full_name
    elif len(name) == 3:
        exec "from %s.%s import %s" %(module,name[1],name[2])
        return loader.getTestCaseNames(eval(name[2]))
    elif len(name) == 2:
        exec 'from %s import %s' % (module,name[1])
        tests = []
        for _name, obj in inspect.getmembers(sys.modules[full_name]):
            if inspect.isclass(obj) and
issubclass(obj,unittest.TestCase):
                exec "from %s.%s import %s" %
(module,name[1],obj.__name__)
                tests.append(loader.getTestCaseNames(obj))
        return tests



if __name__ == "__main__":
    input = "tests.testfile"
    module = input.split('.')[0]
    _tests = get_test_names(input,module)
    print _tests


So guys, can you kindly point me to a more Pythonic, more readable and
possible more short way to acheive this? I will really appreciate any
help. Many thanks in advance.

Best regards,
Oltmans