Rename files in subfolders by specific format in Python

Question

I have a folder with lots of subfolders. Each of subfolders has different type of image files. I'm trying to rename those files by specific format. Data looks like this:

folder
        \ sub1\file0.jpg
        \ sub1\file1.jpg
        \ sub1\file2.png
        .
        .
        .
        \ sub2\xxx.png
        \ sub2\yyy.jpg
        \ sub2\zzz.png
        .
        .
        .

Desired output:

folder
        \ sub1\file-01.jpg
        \ sub1\file-02.jpg
        \ sub1\file-03.png
        .
        .
        .
        \ sub2\file-01.png
        \ sub2\file-02.jpg
        \ sub2\file-03.png
        .
        .
        .

By far, I have tried following code but it doesn't work out.

import os

dir_name = "D:/folder"     
for root, dirs, files in os.walk(dir_name, topdown=False):
    for file in files:
        file_name = os.path.splitext(file)[0]#file name no ext
        extension = os.path.splitext(file)[1]
        dir_name = os.path.basename(root)
        os.rename(root+"/"+file, root+"/"+"file"+"s%"+extension)

"It doesn't work [out]" may be an accurate description of what happens, but we need a bit more. Did you try to see what each step does by insterting `print` commands between each step with the intermediate results? — Jongware, Nov 30 '18 at 09:52
`os.rename(root+"/"+file, root+"/"+"file"+"s%"+extension)` `s%` are you sure you're not missing your index and the proper formatting? — Jean-François Fabre, Nov 30 '18 at 09:59
you could have an increment counter for each type of extension, and reinitialize them for every new sub folder — Surya Tej, Nov 30 '18 at 10:00

Rakesh · Accepted Answer · 2018-11-30T10:43:15.773

2

This is one approach using enumerate.

Demo:

import os

dir_name = "D:/folder"      
for root, dirs, files in os.walk(dir_name, topdown=False):
    for num, file in enumerate(files, 1):   #enumerate to get number
        src =  os.path.join(root, file)
        file_s = os.path.splitext(file)
        dest = os.path.join(root, "{0}-{1}.{2}".format(file_s[0], str(num).rjust(2, "0"), file_s[1]))   #Form destination file name
        os.rename(src, dest)   #Rename.

edited Nov 30 '18 at 10:43

answered Nov 30 '18 at 10:01

Rakesh

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you can lose the `"{0}-{1}.{2}"` for just `"{}-{}.{}"` – Jean-François Fabre Nov 30 '18 at 10:06
1

be careful about `file.split(".")`. Files can contain several dots. That's why `os.path.splitext` exists. – Jean-François Fabre Nov 30 '18 at 10:07
@Jean-FrançoisFabre. Thank you. – Rakesh Nov 30 '18 at 10:43
Thank you. Sorry maybe i didn't explain very clearly. I have tried with your code. It renamed file sub1\file0.jpg to sub1\file0-01..jpg, sub2\xxx.png to sub2\xxx-01..png; which is slightly different to my desired output: sub1\file0.jpg to sub1\file-01.jpg, sub2\xxx.png to sub2\file-01.png. – ah bon Nov 30 '18 at 11:02
1

`dest = os.path.join(root, "{}-{}.{}".format("file", str(num+100).rjust(2, "0"), file_s[1]))` ? – Rakesh Nov 30 '18 at 11:15
dest = os.path.join(root, "{}-{}.{}".format("file", str(num+00).rjust(2, "0"), file_s[1])) – ah bon Nov 30 '18 at 11:43
The code above works, but it generates two points as follows: file-01..jpg – ah bon Nov 30 '18 at 12:31
1

use `"{}-{}{}".` – Rakesh Nov 30 '18 at 12:33

score 1 · Answer 2 · answered Nov 30 '18 at 10:03

os.rename(root+"/"+file, root+"/"+"file"+"s%"+extension)

You're using the %s string formatting syntax wrong (I'm assuming that's what you intend to do). Read more about it here. Just as a reminder, you need an actual variable to be inserted in place of %s. I'm sure you can figure out how to implement that. (the other answer gives a possible solution, too)

In fact, I'd suggest using string formatting for root, file, and extension as well - and while you're at that, consider using f-strings instead of the %s syntax.

Rename files in subfolders by specific format in Python

2 Answers2