What is __pycache__?

A __pycache__ folder is created when you use the line: import file_name. or try to get information from another file you have created. This makes it a little faster when running your program the second time to open the other file.

At the time when you run a program in python, the interpreter compiles it to bytecode first and after compilation interpreter stores it in the __pycache__ folder. So when you look in there you will find a bunch of files sharing the names of the .py files in your project's folder, you will see that their extensions will be either .pyc or .pyo. These files are bytecode-compiled and optimized bytecode-compiled versions of your program's files, respectively.