Addon to run Python script

I’m looking for a script that opens up the file-name browser so that a python script can be selected, then runs that script directly from the file (no need to mess with the text editor). Preferably, be able to open the dialog to the last python file so run. Most apps have a “File/Run Script” operation like this but Blender does not seem to. So I want a File/Import/Python tool that does so.

This is because python scripts are being machine-generated from an external app; my users have to repeatedly open the text editor to open the script, or copy/paste into an empty text editor. Please just trust me that this is a good idea and stick to the question of where there is a “Run Script” or offering up how to produce a simple one, thanks.