How to Prevent Python from Generating .pyc Files

Python typically compiles source code (.py files) into bytecode (.pyc files) to enhance execution speed. However, you may encounter instances where you prefer to execute the interpreter without creating .pyc files.

According to "What's New in Python 2.6 - Interpreter Changes," you can suppress the creation of .pyc or .pyo files by using the following methods:

• Command-line Option:

Run your program using the syntax: python -B prog.py. The -B switch prevents the generation of bytecode.

• Environment Variable:

Set the PYTHONDONTWRITEBYTECODE environment variable to 1 before executing the interpreter. This setting is reflected in the sys.dont_write_bytecode variable within Python programs, allowing you to alter the interpreter's behavior dynamically.

Additional Considerations:

• Performance Impact: Disabling bytecode generation can affect Python performance negatively. Bytecode serves as a form of caching, improving execution speed.
• PYTHONDONTWRITEBYTECODE Option: Configuring Python with PYTHONDONTWRITEBYTECODE=1 can have performance drawbacks. Refer to PEP-304 and PEP-3147 for specific details.
• Performance Benchmarking: For more in-depth information on the performance implications, consider reviewing https://github.com/python/cpython.