Operations on Any values

You can do anything using a value with type Any, and type checkerdoes not complain:

def f(x: Any) -> int:
    # All of these are valid!
    x.foobar(1, y=2)
    print(x[3] + 'f')
    if x:
        x.z = x(2)
    open(x).read()
    return x

Values derived from an Any value also often have the type Anyimplicitly, as mypy can’t infer a more precise result type. Forexample, if you get the attribute of an Any value or call aAny value the result is Any:

def f(x: Any) -> None:
    y = x.foo()  # y has type Any
    y.bar()      # Okay as well!

Any types may propagate through your program, making type checkingless effective, unless you are careful.