basic tests for os popen particularly useful for platforms that fake popen test that commandlines get down as we expect to do this we execute python c import sys printsys argv restofcommandline this results in python being spawned and printing the sys argv list we can then eval the result of this and see what each argv was test that command lines get down as we expect to do this we execute python c import sys print sys argv rest_of_commandline this results in python being spawned and printing the sys argv list we can then eval the result of this and see what each argv was quote embedded space for cmdline strip off argv 0
import unittest
from test import support
import os, sys

if not hasattr(os, 'popen'):
    raise unittest.SkipTest("need os.popen()")






python = sys.executable
if ' ' in python:
    python = '"' + python + '"'     

@support.requires_subprocess()
class PopenTest(unittest.TestCase):

    def _do_test_commandline(self, cmdline, expected):
        cmd = '%s -c "import sys; print(sys.argv)" %s'
        cmd = cmd % (python, cmdline)
        with os.popen(cmd) as p:
            data = p.read()
        got = eval(data)[1:] 
        self.assertEqual(got, expected)

    def test_popen(self):
        self.assertRaises(TypeError, os.popen)
        self._do_test_commandline(
            "foo bar",
            ["foo", "bar"]
        )
        self._do_test_commandline(
            'foo "spam and eggs" "silly walk"',
            ["foo", "spam and eggs", "silly walk"]
        )
        self._do_test_commandline(
            'foo "a \\"quoted\\" arg" bar',
            ["foo", 'a "quoted" arg', "bar"]
        )
        support.reap_children()

    def test_return_code(self):
        self.assertEqual(os.popen("exit 0").close(), None)
        status = os.popen("exit 42").close()
        if os.name == 'nt':
            self.assertEqual(status, 42)
        else:
            self.assertEqual(os.waitstatus_to_exitcode(status), 42)

    def test_contextmanager(self):
        with os.popen("echo hello") as f:
            self.assertEqual(f.read(), "hello\n")

    def test_iterating(self):
        with os.popen("echo hello") as f:
            self.assertEqual(list(f), ["hello\n"])

    def test_keywords(self):
        with os.popen(cmd="exit 0", mode="w", buffering=-1):
            pass

if __name__ == "__main__":
    unittest.main()