Python test whole script

Question

I have a Python script. I use unittest for tests, but how can I test whole script.

My idea is something like this:

def test_script(self):
 output=runScript('test.py --a 5 --b 3')
 self.assertEqual(output, '8') 

test.py takes argument a and b and print a+b, in this case 8

Answer 1

You can use the subprocess library to call a script and capture the output.

import subprocess
p = subprocess.Popen(
 ['./test.py', '--a', ...],
 stdout=subprocess.PIPE,
 stderr=subprocess.STDOUT
)
print p.stdout.read()

Answer 2

Not sure this is what you wanted, use python unittest to wrap up the blackbox testing

import unittest # install and import

wrap your test in TestCase

class ScriptTest(unittest.TestCase):
 def test_script(self):
 output=runScript('test.py --a 5 --b 3')
 self.assertEqual(output, '8')

add TestCase to unittest

if __name__ == '__main__':
 suite = unittest.TestLoader().loadTestsFromTestCase(ScriptTest)
 unittest.TextTestRunner(verbosity=2).run(suite)