The py launcher is optionally installed during the setup process when you first install Python on Windows. At one point, you’ll be prompted to do so, as per the screenshots shown below.

If you see Command python setup.py egg_info failed with error code 1 when Installing Python, then the setup tool on your computer might not be installed or updated.

setup.py is normally used by Python to install the module it’s associated with, and can also be used to direct Python to compile C extensions for that module.

Python modules are typically installed using a package manager called 'pip', which launches a 'setup.py' file that is made available by the developer of the package for installation purposes.

This process occurs automatically in the background by PIP running the main setup.py script that comes as part of the package structure.