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Python unittest assertIsNone()用法及代码示例


assertIsNonePython中的()是单元测试库函数,用于单元测试中以检查输入值是否为None。此函数将使用两个参数作为输入,并根据断言条件返回布尔值。如果输入值等于无assertIsNone()将返回true,否则返回false。

用法: assertIsNone(testValue, message)

参数: assertIsNone()接受以下列出的两个参数并作解释:

  • testValue:将测试变量作为输入值以检查是否与None相等
  • message:作为测试消息失败时显示的消息的字符串语句。

下面列出了两个不同的示例,它们说明了给定assert函数的正面和负面测试案例:

示例1:否定测试用例



Python3

# unit test case 
import unittest 
  
class DummyClass:
  x = 5
  
class TestMethods(unittest.TestCase):
    # test function  
    def test_negative(self):
        firstValue = "geeks"
        # error message in case if test case got failed 
        message = "Test value is not none."
        # assertIsNone() to check that if input value is none 
        self.assertIsNone(firstValue, message) 
  
if __name__ == '__main__':
    unittest.main()

输出:

F
======================================================================
FAIL:test_negative (__main__.TestMethods)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "p1.py", line 14, in test_negative
    self.assertIsNone(firstValue, message)
AssertionError:'geeks' is not None:Test value is not none.

----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (failures=1)

示例2:正测试用例

Python3

# unit test case 
import unittest 
  
class DummyClass:
  x = 5
  
class TestMethods(unittest.TestCase):
    # test function  
    def test_positive(self):
        firstValue = None
        # error message in case if test case got failed 
        message = "Test value is not none."
        # assertIsNone() to check that if input value is none 
        self.assertIsNone(firstValue, message) 
  
if __name__ == '__main__':
    unittest.main()

输出:

.
----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

参考:https://docs.python.org/3/library/unittest.html




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注:本文由纯净天空筛选整理自Shivam.Pradhan大神的英文原创作品 Python unittest – assertIsNone() function。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。