example.txt

$ coverage run test.py
...
----------------------------------------------------------------------
Ran 3 tests in 0.000s

OK
$ coverage report
Name                                                                                                Stmts   Miss  Cover
-----------------------------------------------------------------------------------------------------------------------
/Users/wolever/code/sandbox/env/sandbox/lib/python2.7/site-packages/pkg_resources/_vendor/six         444    442     1%
/Users/wolever/code/sandbox/env/sandbox/lib/python2.7/site-packages/pkg_resources/extern/__init__      35     32     9%
sample                                                                                                  6      0   100%
test                                                                                                   11      0   100%
-----------------------------------------------------------------------------------------------------------------------
TOTAL                                                                                                 496    474     4%
$ nosetests --with-coverage
...
Name     Stmts   Miss  Cover   Missing
--------------------------------------
sample       6      0   100%   
----------------------------------------------------------------------
Ran 3 tests in 0.008s

OK

sample.py

def sum(num1, num2):
    return num1 + num2


def sum_only_positive(num1, num2):
    if num1 > 0 and num2 > 0:
        return num1 + num2
    else:
        return None

test.py

from unittest import TestCase, main

from sample import sum, sum_only_positive

class TestSum(TestCase):
    def test_sum(self):
        assert sum(5, 5) == 10

    def test_sum_positive_ok(self):
        assert sum_only_positive(2, 2) == 4

    def test_sum_positive_fail(self):
        assert sum_only_positive(-1, 2) is None

if __name__ == "__main__":
    main()