How to Find Files With a Certain Extension Only in Python

1. glob.glob Method to Find Files With Certain Extension
2. os.listdir() Method to Find Files With Certain Extension
3. pathlib.glob Method to Find Files With Certain Extension
4. Find Files With a Certain Extension in the Directory and Its Subdirectories in Python
5. pathlib Module Search Files Recursively

This article introduces different methods to find files with a certain extension only in Python.

glob.glob Method to Find Files With Certain Extension

We could use glob.glob module to find the files with a certain extension only in Python.

import glob

targetPattern = r"C:\Test\*.txt"
glob.glob(targetPattern)

The above codes demonstrate how to find the files with extension txt in the directory C:\Test.

os.listdir() Method to Find Files With Certain Extension

os.listdir() function lists all the files in the given directory, without the file path information. You could extract the files with the specific extension by using str.endswith() function.

>>> import os
>>> fileDir = r"C:\Test"
>>> fileExt = r".txt"
>>> [_ for _ in os.listdir(fileDir) if _.endswith(fileExt)]
['test.txt', 'test1.txt']

You need to construct the full path with os.path.join() function.

>>> import os
>>> fileDir = r"C:\Test"
>>> fileExt = r".txt"
>>> [os.path.join(fileDir, _) for _ in os.listdir(fileDir) if _.endswith(fileExt)]
['C:\\Test\\test.txt', 'C:\\Test\\test1.txt']

pathlib.glob Method to Find Files With Certain Extension

pathlib module is introduced in Python 3.4 which offers object-oriented filesystem paths. It provides two styles: Windows paths in Windows OS and POSIX paths in Unix-alike systems.

>>> import pathlib
>>> fileDir = r"C:\Test"
>>> fileExt = r"*.txt"
>>> list(pathlib.Path(fileDir).glob(fileExt))
[WindowsPath('C:/Test/test.txt'), WindowsPath('C:/Test/test1.txt')]

The result is represented with WindowsPath, and you could convert the result to the string representation by adding str(), like

>>> [str(_) for _ in pathlib.Path(fileDir).glob(fileExt)]
['C:\\Test\\test.txt', 'C:\\Test\\test.txt']

Find Files With a Certain Extension in the Directory and Its Subdirectories in Python

The pattern C:\Test\*.txt only searches the txt files in the directory C:\Test, but not in its subdirectories. If you want to also get txt files in the subdirectories, you could modify the pattern a bit.

import glob

targetPattern = r"C:\Test\**\*.txt"
glob.glob(targetPattern)

The wild cards ** between Test and \*.txt means it should find the txt files both in the directory and its subdirectories.

pathlib Module Search Files Recursively

Similar to adding ** in glob.glob to search files recursively, you can also add ** in pathlib.Path.glob method to find the files with a certain extension recursively.

>>> import pathlib
>>> fileDir = r"C:\Test"
>>> fileExt = r"**\*.txt"
>>> list(pathlib.Path(fileDir).glob(fileExt))
[WindowsPath('C:/Test/test.txt'), WindowsPath('C:/Test/test1.txt'), WindowsPath('C:/Test/sub/test1.txt')]