List all files of certain type in a directory using Python

In python, there are several built-in modules and methods for file handling. These functions are present in different modules such as os, glob, etc. This article helps you find out many of the functions in one place which gives you a brief knowledge about how to list all the files of a certain type in a directory by using python programming.

So there are three certain extensions such as

• Using os. walk()
• Using os. listdir()
• Using glob. glob()

Directory used:

image of root folder having path name D:\GFG

Using os.walk() function

In python programming, there are different os modules which enable several methods to interact with the file system. As mentioned above it has walk() function which helps us to list all the files in the specific path by traversing the directory either by a bottom-up approach or by a top-down approach and return 3 tuples such as root, dir, files

Here root is the root directory or root folder, dir is the subdirectory of the root directory and files is the files under the root directory and it’s a subdirectory.

Syntax:

os.walk(r’pathname’)

Python

import os
# traverse whole directory
for root, dirs, files in os.walk(r'D:\GFG'):
    # select file name
    for file in files:
        # check the extension of files
        if file.endswith('.png'):
            # print whole path of files
            print(os.path.join(root, file))

Output:

D:\GFG\gfg_png_file.png

The output of  os.walk() function

Using os. listdir() function

Os has another method which helps us find files on the specific path known as listdir(). It returns all the file names in the directory specified in the location or path as a list format in random order. It excludes the ‘.’ and ‘..’ if they are available in the input folder.

Syntax:

os.listdir(r’pathname’)

Python

import os
# return all files as a list
for file in os.listdir(r'D:\GFG'):
     # check the files which are end with specific extension
    if file.endswith(".png"):
        # print path name of selected files
        print(os.path.join(r'C:\GFG\Screenshots', file))

Output:

D:\GFG\gfg_png_file.png

The output of os.listdir() function

Using glob. glob() function:

In the previous examples, we have to iterate over a list of files in a directory having name match with the particular extensions or patterns. But glob modules gives the facility to find a list of files with particular extensions or pattern. This function has two parameters one is path-name with a specific pattern which filters out all the files and returns the files as a list. Another Parameter named as recursive by default it is off means false. When its value is true then the function searches its directory along with its subdirectory. All wild cards are allowed here like’?’,’*’ etc.

Syntax:

glob.glob(path name, recursive=True)

Python

import glob
import os
# glob.glob() return a list of file name with specified pathname
for file in glob.glob(r''D: \GFG' + "**/*.png", recursive=True):
  # print the path name of selected files
    print(os.path.join(r''D: \GFG', file))

Output:

D:\GFG\gfg_png_file.png

The output of glob.glob() function