Skip to content
Guide Docs

Python Inner Working

Python Bytecode and Virtual Machine

When you run a Python script, the process involves several steps to convert your human-readable code into something that the computer can execute efficiently. Here’s a detailed explanation:

python VM image

  1. Python Source Code (.py file):

    • This is the code you write in a text editor or IDE, saved with a .py extension.

  2. Compilation to Bytecode:

    • When you run a Python script (e.g., python guide.py), Python first compiles the source code into bytecode. This step is mostly hidden from the user.
    • Bytecode:
      • Bytecode is a low-level, platform-independent representation of your source code.
      • It is designed to be efficient for execution by the Python Virtual Machine (VM).
      • Bytecode files typically have a .pyc extension and are stored in a __pycache__ directory.

  3. Python Virtual Machine (VM):

    • The Python VM is responsible for executing the compiled bytecode.
    • The VM interprets the bytecode and performs the necessary operations on the underlying hardware.

  4. Benefits of Bytecode:

    • Platform Independence: Bytecode can be executed on any platform that has a compatible Python VM.
    • Faster Execution: Since bytecode is a more compact and efficient representation of your source code, it generally executes faster than interpreting source code directly.

  5. Compiled Python Files (.pyc files):

    • These files contain the bytecode and are often referred to as frozen binaries.
    • They allow Python programs to start faster since the compilation step is skipped.

Happy coding!