In Python, why is a tuple hashable but not a list?

Question

Here below when I try to hash a list, it gives me an error but works with a tuple. Guess it has something to do with immutability. Can someone explain this in detail ?

Answer 1

Because a list is mutable, while a tuple is not. When you store the hash of a value in, for example, a dict, if the object changes, the stored hash value won't find out, so it will remain the same. The next time you look up the object, the dictionary will try to look it up by the old hash value, which is not relevant anymore.

To prevent that, python does not allow you to has mutable items.