Why python does not need to be compiled?

Answer 1

Compilation tends to be non-portable: a Windows binary doesn't directly work on OS X, but interpreted source code does.

On the flip side, though python's code is easier to read than binary, interpretation (which is done every time, while compilers interpret once) is slower.

On modern equipment the difference often doesn't matter much to people.

Answer 2

Python is an interpreted language. Its interpreter executes each statement line by line. If there is an error in that statement it throws an error and stop right there.