Using glob.glob in python - Findings and thingies

When using glob.glob in Python you might experience some unexpected results. Lets say you have the following directory content.

andre@Users-MBP:~/dev/globdemo% ls -gnGl
total 0
-rw-r--r--  1 20  0 Feb  7 21:51 2019-02-05-demo1.md
-rw-r--r--  1 20  0 Feb  7 21:51 2019-02-06-demo2.md
-rw-r--r--  1 20  0 Feb  7 21:51 2019-02-07-demo3.md

Using the following simple program will create some unexpected output at least at a first glance.

import os, glob

path = '/Users/Andre/dev/globdemo'
for file in glob.glob( os.path.join(path, '*.*')):
    print(file)

This will print the following:

/Users/Andre/dev/globdemo/2019-02-06-demo2.md
/Users/Andre/dev/globdemo/2019-02-07-demo3.md
/Users/Andre/dev/globdemo/2019-02-05-demo1.md

As you can see the order of files is different from the one using ls. This is because glob.glob is basically just a wrapper for os.listdir which returns the directory contents in arbitrary order. On MacOS you will get the same order for your output when using -f.

andre@Users-MBP:~/dev/globdemo% ls -gnGfl
total 0
drwxr-xr-x   5 20  160 Feb  7 21:51 .
drwxr-xr-x  21 20  672 Feb  7 21:58 ..
-rw-r--r--   1 20    0 Feb  7 21:51 2019-02-06-demo2.md
-rw-r--r--   1 20    0 Feb  7 21:51 2019-02-07-demo3.md
-rw-r--r--   1 20    0 Feb  7 21:51 2019-02-05-demo1.md

If you need your files sorted in python you can simply solve this by using sorted in your program.

import os, glob

path = '/Users/Andre/dev/globdemo'
for file in sorted(glob.glob( os.path.join(path, '*.*'))):
    print(file)

Running this slightly modified program will create the following output:

andre@Users-MBP:~/dev% python3 globdemosorted.py
/Users/Andre/dev/globdemo/2019-02-05-demo1.md
/Users/Andre/dev/globdemo/2019-02-06-demo2.md
/Users/Andre/dev/globdemo/2019-02-07-demo3.md