How to build rpm?

Question

Building projects

There is a project (code in python)
When building an rpm, you need to:
change file A (there are diffs)
add file B
How to describe this in a spec file?

Answer 1

Perform an action after uploading files
%post -p /usr/bin/patch ...
Well, remove the delta file after checking the success of patch

Answer 2

Of course, I don't know how correct this is, but looking at other people's specs, I usually do this:
Patch0: [patch-file-name].patch
%prep
...
%patch0 -p1 -b .[backup-extension]
Add the file can be patched with a zero length file