python script to concatenate all the files in the directory into one file

Question

I have written the following script to concatenate all the files in the directory into one single file.

Can this be optimized, in terms of

1. idiomat

Answer 1

Use shutil.copyfileobj to copy data:

import shutil

with open(outfilename, 'wb') as outfile:
    for filename in glob.glob('*.txt'):
        if filename == outfilename:
            # don't want to copy the output into the output
            continue
        with open(filename, 'rb') as readfile:
            shutil.copyfileobj(readfile, outfile)

shutil reads from the readfile object in chunks, writing them to the outfile fileobject directly. Do not use readline() or a iteration buffer, since you do not need the overhead of finding line endings.

Use the same mode for both reading and writing; this is especially important when using Python 3; I've used binary mode for both here.