How do I modify program files in Python?

Question

In the actual window where I right code is there a way to insert part of the code into everyline that I already have. Like insert a comma into all lines at the first spot>?

Answer 1

You need a file editor, not python.

1. Install the appropriate VIM variant for your operating system
2. Open the file you want to modify using VIM
3. Type: :%s/^/,/
4. Type: :wq