Read files sequentially in order

Question

I have a number of files in a folder with names following the convention:

0.1.txt, 0.15.txt, 0.2.txt, 0.25.txt, 0.3.txt, ...

I need to read them one by one and manipulate the data inside them. Currently I open each file with the command:

import os
# This is the path where all the files are stored.
folder path = '/home/user/some_folder/'
# Open one of the files,
for data_file in os.listdir(folder_path):
    ...

Unfortunately this reads the files in no particular order (not sure how it picks them) and I need to read them starting with the one having the minimum number as a filename, then the one with the immediate larger number and so on until the last one.

You'll need to sort the files using a natural sort. – Martijn Pieters Jan 22 '14 at 17:00 — Martijn Pieters, Jan 22 '14 at 17:00

score 8 · Accepted Answer · edited Apr 07 '18 at 22:41

8

A simple example using sorted() that returns a new sorted list.

import os
# This is the path where all the files are stored.
folder_path = 'c:\\'
# Open one of the files,
for data_file in sorted(os.listdir(folder_path)):
    print data_file

You can read more here at the Docs

Edit for natural sorting:

If you are looking for natural sorting you can see this great post by @unutbu

edited Apr 07 '18 at 22:41

Leniel Maccaferri

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answered Jan 22 '14 at 17:03

Kobi K

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5

You need to be careful with sorting strings. Sorting ```['1','2','10']``` will return ```['1','10','2']``` – wnnmaw Jan 22 '14 at 17:05
1

@wnnmaw i accept the comment see the edit. – Kobi K Jan 22 '14 at 17:10
1

Thank you @KobiK, works like a charm! – Gabriel Jan 22 '14 at 17:46
Pypi natsort worked for my numbered `.png` files. – mLstudent33 Apr 12 '19 at 09:17

Read files sequentially in order

1 Answers1