Saturday, September 27, 2025
HomeLanguagesPython unittest – assertFalse() function

Python unittest – assertFalse() function

assertFalse() in Python is a unittest library function that is used in unit testing to compare test value with false. This function will take two parameters as input and return a boolean value depending upon the assert condition. If test value is false then assertFalse() will return true else return false.

Syntax: assertFalse(testValue, message)

Parameters: assertFalse() accepts two parameters which are listed below with explanation:

  • testValue:  variable of a boolean type which is used in the comparison by function
  • message: a string sentence as a message which got displayed when the test case got failed.

Listed below are two different examples illustrating the positive and negative test case for given assert function:

Example 1: Negative Test case

Python3




# unit test case
import unittest
  
class TestStringMethods(unittest.TestCase):
    # test function 
    def test_negative(self):
        testValue = True
        # error message in case if test case got failed
        message = "Test value is not false."
        # assetFalse() to check test value as false
        self.assertFalse( testValue, message)
  
if __name__ == '__main__':
    unittest.main()


Output:

F
======================================================================
FAIL: test_negative (__main__.TestStringMethods)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "p1.py", line 11, in test_negative
    self.assertFalse( testValue, message)
AssertionError: True is not false : Test value is not false.

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

FAILED (failures=1)


Example 2: Positive Test case

Python3




# unit test case
import unittest
  
class TestStringMethods(unittest.TestCase):
    # test function 
    def test_positive(self):
        testValue = False
        # error message in case if test case got failed
        message = "Test value is not false."
        # assertFalse() to check test value as false
        self.assertFalse( testValue, message)
  
if __name__ == '__main__':
    unittest.main()


Output:

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

OK



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

RELATED ARTICLES

Most Popular

Dominic
32322 POSTS0 COMMENTS
Milvus
84 POSTS0 COMMENTS
Nango Kala
6690 POSTS0 COMMENTS
Nicole Veronica
11857 POSTS0 COMMENTS
Nokonwaba Nkukhwana
11913 POSTS0 COMMENTS
Shaida Kate Naidoo
6804 POSTS0 COMMENTS
Ted Musemwa
7073 POSTS0 COMMENTS
Thapelo Manthata
6763 POSTS0 COMMENTS
Umr Jansen
6768 POSTS0 COMMENTS