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