python pytest:捕获标准输出总是失败
问题描述:
我试图从pytest(Python版本3.6)中的stdout/print语句捕获输出。python pytest:捕获标准输出总是失败
这总是失败:
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
结果从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 =======================================================
这是为什么不拍摄?
答
你需要调用readouterr
后打印:
def test_printgreeting(capsys):
"""assert '42' was printed to stdout"""
# capture stdout/stderr
print_greeting()
out, err = capsys.readouterr()
# 42 should be in stdout from sys.stdout.write
assert '42' in out
我的上帝。我用了三个小时的时间对此感到震惊。 >, emf
非常感谢sooooo。 – emf