Why is this an issue?

The unittest module provides assertion methods specific to common types and operations. Both versions will test the same things, but the dedicated one will provide a better error message, simplifying the debugging process.

This rule reports an issue when an assertion can be simplified by using a more specific function. The array below gives a list of assertions on which an issue will be raised, and which function should be used instead:

Original	Dedicated
`assertTrue(x == y)`	`assertEqual(x, y)`
`assertTrue(x != y)`	`assertNotEqual(x, y)`
`assertFalse(x == y)`	`assertNotEqual(x, y)`
`assertFalse(x != y)`	`assertEqual(x, y)`
`assertTrue(x < y)`	`assertLess(x, y)`
`assertTrue(x <= y)`	`assertLessEqual(x, y)`
`assertTrue(x > y)`	`assertGreater(x, y)`
`assertTrue(x >= y)`	`assertGreaterEqual(x, y)`
`assertTrue(x is y)`	`assertIs(x, y)`
`assertTrue(x is not y)`	`assertIsNot(x, y)`
`assertFalse(x is y)`	`assertIsNot(x, y)`
`assertFalse(x is not y)`	`assertIs(x, y)`
`assertTrue(x in y)`	`assertIn(x, y)`
`assertFalse(x in y)`	`assertNotIn(x, y)`
`assertTrue(isinstance(x, y))`	`assertIsInstance(x, y)`
`assertFalse(isinstance(x, y))`	`assertNotIsInstance(x, y)`
`assertEqual(x, round(y, z))`	`assertAlmostEqual(x, y, z)`
`assertAlmostEqual(x, round(y, z))`	`assertAlmostEqual(x, y, z)`
`assertNotEqual(x, round(y, z))`	`assertNotAlmostEqual(x, y, z)`
`assertNotAlmostEqual(x, round(y, z))`	`assertNotAlmostEqual(x, y, z)`
`assertEqual(x, None)`	`assertIsNone(x)`
`assertNotEqual(x, None)`	`assertIsNotNone(x)`
`assertTrue(x is None)`	`assertIsNone(x)`
`assertTrue(x is not None)`	`assertIsNotNone(x)`
`assertFalse(x is None)`	`assertIsNotNone(x)`
`assertFalse(x is not None)`	`assertIsNone(x)`
`assertEqual(x, True)`	`assertTrue(x)`
`assertEqual(x, False)`	`assertFalse(x)`

Noncompliant code example

import unittest
class SomeTest(unittest.TestCase):
  def test_something(self):
    x = foo()
    y = bar()
    self.assertFalse(x == y)  # Noncompliant
    self.assertTrue(x < y)  # Noncompliant

Compliant solution

class SomeTest(unittest.TestCase):
  def test_something(self):
    x = foo()
    y = bar()
    self.assertNotEqual(x, y)
    self.assertLess(x, y)

Resources

Python documentation - the unittest module