I'm trying to capture output from stdout / print statements in pytest (Python version 3.6).
This always fails:
message = 'The meaning of life is not actually 42\n' def print_greeting(): """print 42 to stdout""" # write to stdout sys.stdout.write(message) # this fails # print to stdout print('Message again: ', message) # this fails too def test_printgreeting(capsys): """assert '42' was printed to stdout""" # capture stdout / stderr out, err = capsys.readouterr() print_greeting() # 42 should be in stdout from sys.stdout.write assert '42' in out Results from pytest:
========================================================= test session starts ========================================================== collected 1 item test.py The meaning of life is not actually 42 F =============================================================== FAILURES =============================================================== __________________________________________________________ test_printgreeting __________________________________________________________ test.py:42: in test_printgreeting assert '42' in out E AssertionError: assert '42' in '' ======================================================= 1 failed in 0.03 seconds ======================================================= Why is this not captured?
