How do I read the number of files in a folder using Python?

Question

How do I read the number of files in a specific folder using Python? Example code would be awesome!

Answer 1

To count files and directories non-recursively you can use os.listdir and take its length.

To count files and directories recursively you can use os.walk to iterate over the files and subdirectories in the directory.

If you only want to count files not directories you can use os.listdir and os.path.file to check if each entry is a file:

import os.path
path = '.'
num_files = len([f for f in os.listdir(path)
                if os.path.isfile(os.path.join(path, f))])

Or alternatively using a generator:

num_files = sum(os.path.isfile(os.path.join(path, f)) for f in os.listdir(path))

Or you can use os.walk as follows:

len(os.walk(path).next()[2])

I found some of these ideas from this thread.

Answer 2

pathlib, that is new in v. 3.4, makes like easier. The line labelled 1 makes a non-recursive list of the current folder, the one labelled 2 the recursive list.

from pathlib import Path

import os
os.chdir('c:/utilities')

print (len(list(Path('.').glob('*')))) ## 1
print (len(list(Path('.').glob('**/*')))) ## 2

There are more goodies too. With these additional lines you can see both the absolute and relative file names for those items that are files.

for item in Path('.').glob('*'):
    if item.is_file():
        print (str(item), str(item.absolute()))

Result:

boxee.py c:\utilities\boxee.py
boxee_user_catalog.sqlite c:\utilities\boxee_user_catalog.sqlite
find RSS.py c:\utilities\find RSS.py
MyVideos34.sqlite c:\utilities\MyVideos34.sqlite
newsletter-1 c:\utilities\newsletter-1
notes.txt c:\utilities\notes.txt
README c:\utilities\README
saveHighlighted.ahk c:\utilities\saveHighlighted.ahk
saveHighlighted.ahk.bak c:\utilities\saveHighlighted.ahk.bak
temp.htm c:\utilities\temp.htm
to_csv.py c:\utilities\to_csv.py