PYTHONDONTWRITEBYTECODE documentation is incorrect

Documentation

PYTHONDONTWRITEBYTECODE is documented in Doc/using/cmdline.rst as:

If this is set to a non-empty string, Python won't try to write .pyc files on the import of source modules.

This is incorrect. The variable is obtained in Python/initconfig.c as:

    int dont_write_bytecode = 0;
    _Py_get_env_flag(use_env, &dont_write_bytecode, "PYTHONDONTWRITEBYTECODE");
    if (dont_write_bytecode) {
        config->write_bytecode = 0;
    }

and _Py_get_env_flag reads the environment variable value as integer, treating non-integer string as 1. Specifically, this means that PYTHONDONTWRITEBYTECODE=0 will not suppress writing .pyc files, even though the environment variable is assigned a non-empty string "0".

Linked PRs

• gh-143144

Inizia da Doc/using/cmdline.rst e confronta il comportamento documentato con Python/initconfig.c, in particolare la chiamata a _Py_get_env_flag mostrata nell’issue. Aggiorna la descrizione della variabile d’ambiente in modo che il parsing degli interi e il comportamento di PYTHONDONTWRITEBYTECODE=0 siano accurati; la documentazione è completa quando la formulazione corrisponde all’implementazione.