if x is "abc": pass if 123 is not y: pass if 123 is \ not y: pass if "123" is x < 3: pass if "123" != x is 3: pass if ("123" != x) is 3: pass if "123" != (x is 3): pass {2 is not ''} {2 is not ''} # Regression test for if values[1is not None ] is not '-': pass # Regression test for https://github.com/astral-sh/ruff/issues/11736 variable: "123 is not y"