Check if GZIP file exists in Python

问题:

I would like to check for the existence of a .gz file on my linux machine while running Python. If I do this for a text file, the following code works:

import os.path
os.path.isfile('bob.asc')

However, if bob.asc is in gzip format (bob.asc.gz), Python does not recognize it. Ideally, I would like to use os.path.isfile or something very concise (without writing new functions). Is it possible to make the file recognizable either in Python or by changing something in my system configuration?

Unfortunately I can't change the data format or the file names as they are being given to me in batch by a corporation.

回答1:

Of course it doesn't; they are completely different files. You need to test it separately:

os.path.isfile('bob.asc.gz')

This would return True if that exact file was present in the current working directory.

Although a workaround could be:

from os import listdir, getcwd
from os.path import splitext, basename

any(splitext(basename(f))[0] == 'bob.asc' for f in listdir(getcwd()))

回答2:

You need to test each file. For example :

if any(map(os.path.isfile, ['bob.asc', 'bob.asc.gz'])):
    print 'yay'

回答3:

After fooling around for a bit, the most concise way I could get the job done was

subprocess.call(['ls','bob.asc.gz']) == 0

which returns True if the file exists in the directory. This is the behavior I would expect from

os.path.isfile('bob.asc.gz')

but for some reason Python won't accept files with extension .gz as files when passed to os.path.isfile.

I don't feel like my solution is very elegant, but it is concise. If someone has a more elegant solution, I'd love to see it. Thanks.