How do I concatenate files in Python?

Question

I have multiple (between 40 and 50) MP3 files that I'd like to concatenate into one file. What's the best way to do this in Python?

Use fileinput module to loop through each line of each file and write it to an output file? Outsource to windows copy command?

Does this answer your question? [Python concatenate text files](https://stackoverflow.com/questions/13613336/python-concatenate-text-files) — Kai Petzke, Aug 14 '20 at 18:36

score 52 · Accepted Answer · edited Nov 18 '12 at 23:09

52

Putting the bytes in those files together is easy... however I am not sure if that will cause a continuous play - I think it might if the files are using the same bitrate, but I'm not sure.

from glob import iglob
import shutil
import os

PATH = r'C:\music'

destination = open('everything.mp3', 'wb')
for filename in iglob(os.path.join(PATH, '*.mp3')):
    shutil.copyfileobj(open(filename, 'rb'), destination)
destination.close()

That will create a single "everything.mp3" file with all bytes of all mp3 files in C:\music concatenated together.

If you want to pass the names of the files in command line, you can use sys.argv[1:] instead of iglob(...), etc.

edited Nov 18 '12 at 23:09

Clint

4,255
1
20
19

answered Jun 16 '09 at 13:44

nosklo

217,122
57
293
297

you don't need fullname step there, glob is already producing absolute filenames. – SilentGhost Jun 16 '09 at 13:48
and you can use iglob, instead of glob – SilentGhost Jun 16 '09 at 13:49
I have no clue if it will cause continuous play or not - guess I'll find out - and maybe ask another question about it...haha. – Owen Jun 16 '09 at 15:14
This solution does impact continuous play - in that it doesn't happen. There's some skipping in the spots where MP3s were joined. This is fine for my application though. – Owen Jul 06 '09 at 14:19
What does the `r` in `r'C:\music'` do? – Nathan Fellman Oct 05 '09 at 06:18
1

Is it just me or is there a colon missing on the for loop line? – maryisdead May 08 '12 at 12:53
Shouldn't the destination's file mode be set to 'a' - append? – Kanguros Mar 25 '15 at 15:42
You can also use: with open('everything.mp3', 'wb') as destination: - and let it close itself in the end – Jose Alban Nov 30 '16 at 10:12

score 35 · Answer 2 · edited May 23 '17 at 11:54

35

Just to summarize (and steal from nosklo's answer), in order to concatenate two files you do:

destination = open(outfile,'wb')
shutil.copyfileobj(open(file1,'rb'), destination)
shutil.copyfileobj(open(file2,'rb'), destination)
destination.close()

This is the same as:

cat file1 file2 > destination

edited May 23 '17 at 11:54

Community

1
1

answered Oct 05 '09 at 07:40

Nathan Fellman

122,701
101
260
319

I tried doing this, but for some reason I just get the first file, and not the second file appended. Both files are mp4 – CMJ Apr 02 '21 at 14:12
Works fine for me! You can do this with one line less by using a with statement. – Dobedani Apr 15 '22 at 14:16

score 6 · Answer 3 · answered Jun 16 '09 at 13:49

6

Hmm. I won't use "lines". Quick and dirty use

outfile.write( file1.read() )
outfile.write( file2.read() )

;)

answered Jun 16 '09 at 13:49

tuergeist

9,171
3
37
58

score 2 · Answer 4 · answered Aug 31 '19 at 16:20

Improving on Clint and nosklo, knowing context manager, I find it cleaner to write this:

import shutil
import pathlib

source_files = pathlib.Path("My_Music").rglob("./*.mp3")
with open("concatenated_music.mp3", mode="wb") as destination:
    for file in source_files:
        with open(file, mode="rb") as source:
            shutil.copyfileobj(source, destination)

How do I concatenate files in Python?

4 Answers4

Linked

Related