如何为print语句编写python单元测试？

Question

我是编写python单元测试的新手，请帮助我为下面的函数编写测试用例，该函数只有print语句而不是return语句

import os
from pwd import getpwuid
from grp import getgrgid
import time

def info(self):
 if self.f:  // if -f  flag pass with file names then it will be trigger
    for i in self.f:
        owner = getpwuid(os.stat(i).st_uid).pw_name
        group = getgrgid(os.stat(i).st_gid).gr_name
        per = oct(os.stat(i).st_mode)[-3:]
        t = os.stat(i).st_mtime
        print("{} is owned by: {} , group by {} with "
              "permission {} and last modified on {}"
              .format(i, owner, group, per, time.ctime(t)))

Answer 1

您可以使用contextlib的^{}

import io
import unittest
from contextlib import redirect_stdout

import lib_containing_info

class TestInfo():
    def test_info(self)
        f = io.StringIO()
        with redirect_stdout(f):
            lib_containing_info.info()  # function being tested
        self.assertRegex(f.getvalue(), r"is owned by: ")