How to use glob in Python

Motivation

Sometimes you need to find files across multiple directories and / or directory hierarchies according to certain pattern.

E.g. find all image files with the jpg extension

You can use it to find files in a directory by using wildcard semantics.
Let’s say we have a directory structure like this:

glob_test/
|-- dir_a/ 
    |-- text_01.txt
    |-- text_02.txt
    |-- text_03.txt
|-- dir_b/ 
    |-- text_01.txt 
    |-- text_02.txt
    |-- text_03.txt
|-- test_glob.py

Find files in directory

Let us find all text files in dir_a:

import glob

def test_glob_files():
    text_files = glob.glob("./dir_a/text_*.txt")
    print(text_files)
    assert len(text_files) != 0

Find a file across multiple directories

Let’s find all occurences of text_01.txt in all directories

def test_glob_dirs():
    text_files = glob.glob("./dir_*/text_01.txt")
    print(text_files)
    assert len(text_files) != 0