Python – Change one specific extension type of files in a directory that contains multiple types of extensions

smrt_file_renamer.py

import os
import re
 
src_drct='/home/gmastrokostas/tmp'
 
for files in os.listdir(src_drct):
 
    if files.endswith('.txt'):
        oldF = os.path.join(src_drct, files)
        #midF = re.split(r'\.', files)#This works too.
        midF = os.path.splitext(files) #It creates a list and splits the name of the file from the extension.
        newF = oldF.replace('.txt', '.py')#Simple replacement.
        out = os.rename(oldF, newF)