See how native functions were written - Python

Question

There is a practical way to check, how is written the code of any Python function, example max()?

Answer 1

When it is a function written in Python, you can use the module inspect.

For example:

def somar(a, b):
    return a + b

In doing print(inspect.getsource(somar)) you will have the exit as string:

def somar(a, b):
    return a + b

This will work for modules, classes, methods, functions and others; only it will not work for objects that have been implemented in C, such as the module sys and the functions min and max. For this, you will need to look at the source files, at official repository.

If the intention is to thoroughly analyze what happens, I suggest using the module dis. With it you can, for example, check the opcode which will be executed by the interpreter:

>>> print( dis.dis(somar) )
  2           0 LOAD_FAST                0 (a)
              2 LOAD_FAST                1 (b)
              4 BINARY_ADD
              6 RETURN_VALUE
None

What each command means you can read in the documentation.

Answer 2

All Python source code (standard implementation) is on Github and can be consulted. The role max().