I am a beginner so if this question sounds stupid, please bear with me. 
I am wondering that when we write code for username/password check in python, if it is not compiled to exe ie script state, won't people will easily open the file and remove the code potion that is doing the password check?
I am assuming that the whole program is entirely written in python, no C or C++.
Even if I use a program like py2exe it can be easily decompiled back to source code. So, does that mean it is useless to do a password check?
How do professional programmers cope with that?
One way would be to store the password in a hash form of any algorithm and check if the hash of the password given is equal to the stored password hash.
The second way might be to take a password like "cat" and convert them to ascii and and add them up and store the sum. Then you can compare the given password's ascii sum to the one you stored.
OR you can combine them both! Maybe also hash the ascii sum and compare the given pass word's ascii sun's hash.
These are the three ways I know at least. And you can use chr or ord default function in python to convert to and back repeatedly to ascii. And you can use hashlib to hash.
Python Password Protection