How can i rename an android phone's .jpg file in a specific pattern using python 3?

I'm still very new to programming with Python 3 and know almost nothing about it. I was told that Python is both powerful and easy to learn.

Right now I'm trying to rename some .jpg files from my android phone into a certain pattern. The usual pattern of a normal .jpg file(taken with the camera) from my android phone looks like this: YYYYMMDD_hhmmss.jpg and im trying to change it into this pattern: YYYY-MM-DD hh-mm-ss.jpg

This is the code i wrote so far:

import re
import os

for filename in os.listdir(".") #here is the path to the .jpg files
    m = re.match(r"(\d{8})_(\d{6})\.jpg", filename)
    if m:
        newname = (r"(\d{4})-(\d{2})-(\d{2}) (\d{2})-(\d{2})-(\d{2})\.jpg)
        if not os.path.exists(newname):
            os.rename(filename, newname)

When i run the program the shell alone doesn't really show me an error message. It only says this:

=====RESTART: (a path that leads to the .py file that my code is written in)======

After that i ran the debugger through the Python Shell and it said:

KeyError:(, '(\d{8})_(\d{6})\.jpg'0) (in the debugger)

_tkinter.TclError: invalid command name ".47860048.41027664.41027120" (in the shell after debugging)

I dont know what it means or what i can do to make this work.

Thanks in advance for every answer i might get.

Solution

You should use re.sub and backreference

import re
import os

FOLDER_PATH = "."   #set your path here
for filename in os.listdir(FOLDER_PATH):    
    newname = re.sub("(\d{4})(\d{2})(\d{2})_(\d{2})(\d{2})(\d{2})\.jpg"
                , r"\1-\2-\3 \4-\5-\6.jpg"
                , filename)
    if (newname != filename and (not os.path.exists(os.path.join(FOLDER_PATH, newname)))):
        os.rename(os.path.join(FOLDER_PATH, filename), os.path.join(FOLDER_PATH, newname))