TypeError isinstance arg 2 must be a type or tuple of types

This error occurs when the second argument passed to the isinstance() function is not a type or a tuple of types.

For example, if we have the following code:

x = 5
if isinstance(x, "int"):
    print("x is an integer")

We will get the following error:

TypeError: isinstance() arg 2 must be a type or tuple of types

The second argument should be a type, not a string. To fix this error, we can change the code to:

x = 5
if isinstance(x, int):
    print("x is an integer")

In this case, we pass the int type as the second argument to the isinstance() function