Confusion between equality ==, != and identity is in conditional expressions can lead to unintended behavior.
1def notequals_operator_noncompliant():
2    phrase = "Thisisstring"
3    # Noncompliant: uses checks for equality instead of identity.
4    if phrase != None:
5        print(True)1def isnot_operator_compliant():
2    phrase = "Thisisstring"
3    # Compliant: uses the correct mechanism for checking the identity.
4    if phrase is not None:
5        print(True)