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

Doc/using/cmdline.rst から始め、文書化された動作を Python/initconfig.c と比較します。特に、issue に示されている _Py_get_env_flag 呼び出しを確認してください。環境変数の説明を更新し、整数の解析と PYTHONDONTWRITEBYTECODE=0 の動作が正確になるようにします。文言が実装と一致すれば、ドキュメントは完了です。