How to create a python list with the number of file in each sub directory of a directory

Question

I have a main directory(root) which countain 6 sub directory. I would like to count the number of files present in each sub directory and add all to a simple python list .

For this result : mylist = [497643, 5976, 3698, 12, 456, 745]

I'm blocked on that code:

import os, sys
list = []
# Open a file
path = "c://root"
dirs = os.listdir( path )

# This would print all the files and directories
for file in dirs:
   print (file)

#fill a list with each sub directory number of elements
for sub_dir in dirs:
    list = dirs.append(len(sub_dir))

My trying for the list fill doesn't work and i'm dramaticaly at my best...

Finding a way to iterate sub-directory of a main directory and fill a list with a function applied on each sub directory would sky rocket the speed of my actual data science project!

Thanks for your help

Abel

Answer 1

You need to use os.listdir on each subdirectory. The current code simply takes the length of a filepath.

import os, sys
list = []
# Open a file
path = "c://root"
dirs = os.listdir( path )

# This would print all the files and directories
for file in dirs:
   print (file)

#fill a list with each sub directory number of elements
for sub_dir in dirs:
    temp = os.listdir(sub_dir)
    list = dirs.append(len(temp))

Adding this line to the code will list out the subdirectory

Answer 2

You were almost there:

import os, sys

list = []

# Open a file
path = "c://root"
dirs = os.listdir(path)

# This would print all the files and directories
for file in dirs:
    print(file)

for sub_dir in dirs:
    if os.path.isdir(sub_dir):
        list.append(len(os.listdir(os.path.join(path, sub_dir))))

print(list)

Answer 3

You can use os.path.isfile and os.path.isdir

res = [len(list(map(os.path.isfile, os.listdir(os.path.join(path, name))))) for name in os.listdir(path) if os.path.isdir(os.path.join(path, name))]
print(res)

Using the for loop

res = []
for name in os.listdir(path):
    dir_path = os.path.join(path, name)
    if os.path.isdir(dir_path):
        res.append(len(list(map(os.path.isfile, os.listdir(dir_path)))))

Answer 4

As an alternative, you can also utilize glob module for this and other related tasks. I have created a test directory containing 3 subdirectories l , m and k containing 3 test files each.

import os, glob
  
list = []
path = "test" # you can leave this "." if you want files in the current directory

for root, dirs, files in os.walk(path, topdown=True):
   for name in dirs:
     list.append(len(glob.glob(root + '/' +  name + '/*')))

print(list)

Output :

[3, 3, 3]