Python unittest – assertEqual() function
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 caseimport 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 caseimport 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
