File System & Path #

Warning: This post hasn't been updated for over a year. The information may be out of date.

The following code has been adapted for use within Jupyter Lab.
Ref: python 3.x - __file__ does not exist in Jupyter Notebook - Stack Overflow

Enumerate Files #

The best library I have found for this use case is glob.

import glob

List all second level subfolders:

list_sub = []

for folder in glob.glob("**/**/"):
    list_sub.append(folder)

List all subfolders recursively: (credit)

list_sub_r = []

for folder in glob.glob("**/", recursive=True):
    list_sub_r.append(folder)

List all .md files in each subfolder, recursively:

dict_all_files = {}

# for each folder
for folder in glob.glob("**/", recursive=True):
    dict_all_files[folder] = []

    # find all md and txt files in the sub folder
    for file in [glob.glob(folder + "*.md"), glob.glob(folder + "*.txt")]:
        dict_all_files[folder].append(file)

# pretty print
print(json.dumps(dict_all_files, sort_keys=True, indent=4))

Manipulate files #

Check file or folder exists #

Folder: (ref)

import os

folder = "some/folder"

if os.path.isdir(folder): # folder exists
    if not os.listdir(folder): # folder is empty
        print(folder, "is empty")
    else:
        raise Exception(folder + " is not empty")
else: # create folder if doesn't exist
    os.makedirs(folder)
    print("Creating", folder)

File:

import os

file = "some/file.ext"

print(os.path.isfile(file))

Change file name; move file #

Refs:

import os
import re

top_dir = "data"

for subdir, dirs, files in os.walk(top_dir):
    for filename in files:
        if filename.lower().find(" extra text") > 0:
            # get the path to your file
            file_path = os.path.join(subdir, filename)
            # create the new name
            new_file_path = re.sub(' extra text', '', file_path, flags=re.IGNORECASE) # create the new name, case insensitive
            # rename your file
            os.rename(file_path, new_file_path)

A more elaborated use case:

import os

top_dir = "data"

for subdir, dirs, files in os.walk(top_dir):
    for filename in files:
        if filename.endswith(('.xlsx','.ods')):
            # get the path to your file
            file_path = os.path.join(subdir, filename)
            # get filename and file extension
            file_time, file_ext = filename.split(".")
            # the filename is a date in plain English, change it into ISO
            new_file_time = datetime.datetime.strptime(file_time, '%d %B %Y').strftime('%Y-%m-%d')
            # add back extension
            new_file_name = new_file_time + "." + file_ext
            # apply the new name + move path
            new_file_path = os.path.join(top_dir, new_file_name)
            # rename your file
            os.rename(file_path, new_file_path)

Delete file #

Ref: python - Most pythonic way to delete a file which may not exist - Stack Overflow

import os

try:
    os.remove("test.txt")
except OSError:
    pass

Delete empty folders #

Ref: How to delete only empty folders in Python?

import os

top_dir = "data"

for dirpath, dirnames, filenames in os.walk(top_dir, topdown=False):
    for dirname in dirnames:
        full_path = os.path.join(dirpath, dirname)
        if not os.listdir(full_path): 
            os.rmdir(full_path)