Python files (.py) are just text files with a different extension that allows the operating system to easily recognise them. The 'metadata' seen in the Properties window is simply some information that is associated with every file, like the creation date.
The tool you are trying to use is for removing EXIF data from photo's. EXIF data is normally only included in image files, and your tool will not be able to remove it if it doesn't exist.
If you want to remove the information from the properties window before you send the file to others, there is no need to do so. When you send the file to other people normally (e.g. via e-mail) only the contents of the file (and sometimes the filename) is sent, no other metadata.