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NoahVerner
Asked: 2022-05-26 12:52:57 +0800 CST 2022-05-26 12:52:57 +0800 CST

How to correctly apply a regular expression to get the last name (of a file or folder) from a given path and print it in Python?

  • 772

I wrote some code that creates a dictionary that stores all the absolute paths of the folders in the current path as keys , and all their filenames as values ​​, respectively. This code would only apply to paths that have folders that only contain stock images.

The code is the following:

import os
import re
# Main method
the_dictionary_list = {}

for name in os.listdir("."):
    if os.path.isdir(name):
        path = os.path.abspath(name)
        print(f'\u001b[45m{path}\033[0m')
        match = re.match(r'/(?:[^\\])[^\\]*$', path)
        print(match)
        list_of_file_contents = os.listdir(path)
        print(f'\033[46m{list_of_file_contents}')
        the_dictionary_list[path] = list_of_file_contents
        print('\n')
print('\u001b[43mthe_dictionary_list:\033[0m')
print(the_dictionary_list)

The thing is, I want this dictionary to store only the last folder names as keys instead of their absolute paths, so I was planning to use this re /(?:[^\\])[^\\]*$, which would take care of getting the last name (of a file or folder from a path given) and then add those last names as braces in the dictionary inside the for loop.

I wanted to try the above code first to see if it was doing what I wanted, but it wasn't, the value of the variable matchbecame Noneon every iteration, which didn't make sense to me, everything else works fine.

So I would like to know what am I doing wrong here.

python

3 Answers

  1. Best Answer

    You are working more. First of all, the code is not recursive, so it will only scan the first level of subdirectories.

    With the following code the variable subdircontains the name of a subdirectory. To form the complete path I must join base_dirwith subdir. In other words, there you have what you were looking for:

    base_dir = "/home/candid/Pictures/"

for subdir in os.listdir(base_dir):
    path = f"{base_dir}{subdir}"

    After you check that it pathis a directory:

    if os.path.isdir(path):

    You can go in and list it:

        print(f'\u001b[45m{path}\033[0m')
    list_of_file_contents = os.listdir(path)
    print(f'\033[46m{list_of_file_contents}')

    and store the result under the desired key:

        the_dictionary_list[subdir] = list_of_file_contents

    show

    The complete code:

    import os

the_dictionary_list = {}
base_dir = "/home/candid/Pictures/Wallpapers/"

for subdir in os.listdir(base_dir):
    path = f"{base_dir}{subdir}"
    if os.path.isdir(path):
        print(f'\u001b[45m{path}\033[0m')
        list_of_file_contents = os.listdir(path)
        print(f'\033[46m{list_of_file_contents}')
        the_dictionary_list[subdir] = list_of_file_contents
        print('\n')
print('\u001b[43mthe_dictionary_list:\033[0m')
for subdir in the_dictionary_list:
    print(subdir)
    for archivo in the_dictionary_list[subdir]:
        print("    ", archivo)
    • 1

  2. Based on @candid-moe's answer, I decided to rethink the above code in case I wanted to apply it only to the current directory (where the program would be).

    import os
# Main method

the_dictionary_list = {}

for subdir in os.listdir("."):
    if os.path.isdir(subdir):
        path = os.path.abspath(subdir)
        print(f'\u001b[45m{path}\033[0m')
        list_of_file_contents = os.listdir(path)
        print(f'\033[46m{list_of_file_contents}')
        the_dictionary_list[subdir] = list_of_file_contents
        print('\n')
print('\033[1;37;40mThe dictionary list:\033[0m')
for subdir in the_dictionary_list:
    print('\u001b[43m'+subdir+'\033[0m')
    for archivo in the_dictionary_list[subdir]:
        print("    ", archivo)
print('\n')
print(the_dictionary_list)

    This would be useful in case the user wants to run the program with a double click in a specific location ( my personal case ).

    • 1

  3. You can also just useos.path.basename(dir...)

    import os
import re
# Main method
the_dictionary_list = {}

for name in os.listdir("."):
    if os.path.isdir(name):
        path = os.path.basename(name)
        print(f'\u001b[45m{path}\033[0m')

        list_of_file_contents = os.listdir(path)
        print(f'\033[46m{list_of_file_contents}')
        the_dictionary_list[path] = list_of_file_contents
        print('\n')
print('\u001b[43mthe_dictionary_list:\033[0m')
print(the_dictionary_list)

    in such a way that the output is (according to the folders that I have added manually):

    n1
['jaja.jpg', 'jojo.jpg']


n2
['im.jpg']


the_dictionary_list:
{'n1': ['jaja.jpg', 'jojo.jpg'], 'n2': ['im.jpg']}
    • 1