The Python launcher for Windows is a utility which aids in locating and executing of different Python versions.
It allows scripts (or the command-line) to indicate a preference for a specific Python version, and will locate and execute that version.
Unlike the PATH variable, the launcher will correctly select the most appropriate version of Python.
It will prefer per-user installations over system-wide ones, and orders by language version rather than using the most recently installed version.
The launcher was originally specified in PEP 397.
