Edit Filename

[snippsat]

It's not r but f i use string formatting f-string.
Test working.

import os

path = 'C:/Users/Name/Downloads/'
os.chdir(path)
for i in range(ord('a'), ord('c')+1):
    os.rename(f'{path}ppl15{chr(i)}.png', f'{path}ppl139.{i}.png')
print('Finish')

These filename most exists in path Download.

ppl15a.png
ppl15b.png
ppl15c.png

My output:

Output:
ppl139.97.png
ppl139.98.png
ppl139.99.png