assertEqual() in Python is a unittest library function that is used in unit testing to check the equality of two values. This function will take three parameters as input and return a boolean value depending upon the assert condition. If both input values are equal assertEqual() will return true else return false.
Syntax: assertEqual(firstValue, secondValue, message)
Parameters: assertEqual() accept three parameter which are listed below with explanation:
- firstValue variable of any type which is used in the comparison by function
- secondValue: variable of any 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 to test equality of two value def test_negative( self ): firstValue = "Lazyroar" secondValue = "gfg" # error message in case if test case got failed message = "First value and second value are not equal !" # assertEqual() to check equality of first & second value self .assertEqual(firstValue, secondValue, message) if __name__ = = '__main__' : unittest.main() |
Output:
F ====================================================================== FAIL: test_negative (__main__.TestStringMethods) ---------------------------------------------------------------------- Traceback (most recent call last): File "p1.py", line 12, in test_negative self.assertEqual(firstValue, secondValue, message) AssertionError: 'Lazyroar' != 'gfg' - Lazyroar + gfg : First value and second value are not equal! ---------------------------------------------------------------------- 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 to test equality of two value def test_positive( self ): firstValue = "Lazyroar" secondValue = "Lazyroar" # error message in case if test case got failed message = "First value and second value are not equal !" # assertEqual() to check equality of first & second value self .assertEqual(firstValue, secondValue, message) if __name__ = = '__main__' : unittest.main() |
Output:
. ---------------------------------------------------------------------- Ran 1 test in 0.000s OK
Reference: https://docs.python.org/3/library/unittest.html