Python Directory File Listing

How do I list all files in a directory using Python?

With over 10 years of experience in Python development, I’ve found that the os.listdir() function is quite handy for getting both files and directories within a directory. To list only files, you can utilize the os.path’s isfile() function. Here’s a neat way to do this:

from os import listdir
from os.path import isfile, join

# List only files in mypath
onlyfiles = [f for f in listdir(mypath) if isfile(join(mypath, f))]

Alternatively, if you prefer a more streamlined approach that also explores subdirectories, you might consider using os.walk(). Here are two ways to leverage it:

from os import walk

# List files from the top directory quickly
filenames = next(walk(mypath), (None, None, []))[2]  # returns [] if no file

or for a more comprehensive listing:

f = []
for (dirpath, dirnames, filenames) in walk(mypath):

Both methods are effective depending on your specific needs for file retrieval.

As a software engineer who often interacts with file systems, I regularly use the os.listdir() function for a quick directory listing. Simply put, the function call os.listdir("somedirectory") provides a list of all entries in that directory, both files and directories. It’s straightforward and efficient for many basic needs. Here’s how you might use it:

from os import listdir

# List everything in the directory

all_entries = listdir("somedirectory")

This method is particularly useful when you need a fast directory scan without any filtering or additional file information.

In my five years as a data scientist, I’ve often needed to filter out directories and only list files in a given directory. To achieve this efficiently, you can use a one-liner with os.walk(), which is great for getting straight to the file names:

from os import walk

# Quickly retrieve file names

filenames = next(walk(path))[2]

If your application requires absolute paths, here’s another one-liner that combines the directory path with file names, providing a complete path for each file:

from os.path import join

# Create a list of full paths to the files

paths = [join(path, fn) for fn in filenames]

This approach saves time and lines of code when you’re working with file paths in various operations, like data loading or file manipulation.