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How to filter files by extension in Python

How to filter files by extension in Python.

Here's a step-by-step tutorial on how to filter files by extension in Python:

Step 1: Import the os module​

To work with files and directories, we need to import the built-in os module. This module provides various functions for interacting with the operating system.

import os

Step 2: Define the directory path​

Specify the directory path where you want to filter the files. You can either provide an absolute path or a relative path.

directory_path = '/path/to/directory'

Step 3: List all files in the directory​

Use the os.listdir() function to get a list of all files and directories present in the specified directory.

files = os.listdir(directory_path)

Step 4: Filter files by extension​

Iterate over the list of files and use the os.path.splitext() function to split the file name and extension. Compare the extension with the desired extension using an if statement.

desired_extension = '.txt'  # Change this to the desired extension

filtered_files = []
for file in files:
    _, extension = os.path.splitext(file)
    if extension == desired_extension:
        filtered_files.append(file)

Alternatively, you can use a list comprehension to achieve the same result in a more concise way:

filtered_files = [file for file in files if os.path.splitext(file)[1] == desired_extension]

Step 5: Print or process the filtered files​

You can print the filtered file names or perform further processing on them based on your requirements.

for file in filtered_files:
    print(file)

That's it! You now have a list of files filtered by their extension.

Here's the complete code:

import os

directory_path = '/path/to/directory'
files = os.listdir(directory_path)

desired_extension = '.txt'  # Change this to the desired extension

filtered_files = [file for file in files if os.path.splitext(file)[1] == desired_extension]

for file in filtered_files:
    print(file)

Feel free to modify the desired_extension variable to match the extension you want to filter by.