builtin_function_or_method' object is not subscriptable

This error message typically occurs when you try to use square brackets to access an element of an object that is not subscriptable, i.e., it does not support indexing.

For example, if you try to use square brackets to access an element of a built-in function or method in Python, you will get this error message:

>>> len[1, 2, 3]
TypeError: 'builtin_function_or_method' object is not subscriptable

Here, `len` is a built-in function in Python that returns the length of an object, such as a string, list, or tuple. However, it is not subscriptable, so you cannot use square brackets to access its elements.

To fix this error, make sure that you are using square brackets only with objects that support indexing, such as lists, tuples, and strings. If you are unsure whether an object is subscriptable, you can check its type using the `type()` function.