Find a file from a partial filename in python

Question

I am looking for a python script that will find the the exact filename of an existing file in the current directory that this python script will run from, that may be named incrementally.

For example the file could be: file1.dat file2.dat file3.dat ....

So we know that the file name starts with the prefix file and we know that it ends with the sufix .dat.

But we don't know whether it will be file1.dat or file1000.dat or anything inbetween.

So I need a script that will check in the range of say 1-1000 all filenames from file1.dat to file1000.dat, and if it finds the one that does exist in the directory, it returns a success message.

have a look here : https://stackoverflow.com/questions/3964681/find-all-files-in-a-directory-with-extension-txt-in-python — Dadep, Aug 29 '17 at 18:38
Possible duplicate of [Find all files in a directory with extension .txt in Python](https://stackoverflow.com/questions/3964681/find-all-files-in-a-directory-with-extension-txt-in-python) — Dadep, Aug 29 '17 at 18:39

score 8 · Answer 1 · answered Aug 29 '17 at 18:42

8

Try something like this:

import os

path = os.path.dirname(os.path.realpath(__file__))

for f_name in os.listdir(path):
    if f_name.startswith('file') and f_name.endswith('.dat'):
        print('found a match')

answered Aug 29 '17 at 18:42

LeopoldVonBuschLight

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1

This has the possibility of matching files with names like `file-sample.dat` or `file.dat`. – Zach Gates Aug 29 '17 at 18:53
@ZachGates Yes, it does. This was just meant to be a starting point. I'm 100% sure what his naming convention is/will be. – LeopoldVonBuschLight Aug 29 '17 at 19:00

Zach Gates · Answer 2 · 2020-08-03T01:49:17.780

4

I would search with a regex using Python's glob module. Here's a sample expression:

glob.glob(r'^file(\d+)\.dat$')

This will match a filename starting with file, followed by any digits, and ending with .dat. For a deeper explanation on how this regex works, check it out on Regex101, where you can test it, as well.

Note: Your question did not specify, but as a bonus, glob also supports recursive searches.

edited Aug 03 '20 at 01:49

answered Aug 29 '17 at 18:51

Zach Gates

4,045
1
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51

score 2 · Accepted Answer · answered Aug 29 '17 at 18:42

2

Try this:

for i in range(1, 1001):
    if os.path.isfile("file{0}.dat".format(i)):
        print("Success!")
        break
else:
    print("Failure!")

answered Aug 29 '17 at 18:42

Karan Elangovan

688
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user5722540 · Answer 4 · 2017-08-29T18:51:12.290

0

As others have suggested in comments, glob and other options are available,however, personally i find listdir more comfortable.

import os
for file in os.listdir("/DIRECTORY"):
    if file.endswith(".dat") and prefix in file:
        print file

edited Aug 29 '17 at 18:51

answered Aug 29 '17 at 18:46

user5722540

590
8
24

What is `prefix`? I suspect it's `"file"`, and if that is the case, you could end up matching files like `file-sample.dat`, etc. Using the `in` operator, you could even match files like `sample-file.dat` or `ignore-this-file.dat`. – Zach Gates Aug 29 '17 at 18:57

Find a file from a partial filename in python

4 Answers4