I’ve noticed that after running my Python scripts, a pycache folder appears containing .pyc files. I understand that .py is where I write my source code, but what is the specific purpose of the .pyc file? Does it make the code run faster in terms of execution speed, or is it just about the startup time? I’m trying to optimize my deployment pipeline and need to know if I should include these in my version control.
3 answers
The main difference lies in the stage of execution. A .py file contains your human-readable source code. When you run this, the Python interpreter compiles it into "bytecode," which is stored in the .pyc file. This bytecode is a platform-independent intermediate representation. The primary benefit of .pyc files is improved startup time; Python checks the timestamp of the .py file, and if it hasn't changed, it loads the .pyc file directly to skip the compilation step. However, it does not make the actual execution of the logic faster once the program is running, as both eventually run on the Python Virtual Machine (PVM).
Does the Python version you are using change where these files are stored? I remember in older versions of Python they were in the same directory, but now they seem tucked away in a cache folder. I’m curious if this affects how we should manage our .gitignore files for professional projects
Think of the .py file as your draft and the .pyc as the "translated" version that the computer understands more easily. It's strictly for efficiency during the loading phase.
Linda’s analogy is spot on. To add more detail, the "translation" she mentions is what we call Bytecode. This intermediate step is what makes Python so portable across different operating systems.
Jason, you're right! Since Python 3.2, these files are stored in the __pycache__ directory to avoid cluttering source folders. Regarding your question on version control, the industry standard is to exclude .pyc files and the cache folder entirely. Since they are automatically generated and can be platform-specific or version-specific, they don't belong in a repository. This keeps your codebase clean and prevents merge conflicts caused by binary file updates.