A small utility for copying music to a folder with a limit on the number of files per folder (copying music to a USB drive for use in a car)

folders_to_skip.json

{"Folders" : 
    {
        "Comedy": false,
        "Famous": false,
        "Mellow": false,
        "Mixes": ["Youtube Mixes"],
        "Musicals": false,
        "OST - Instrumental": false,
        "Standup": false,
        "XMas": false
    }
}

music_to_car_usb.py

''' This little command-line utility takes music in an existing folder structure and copies it to a 
destination, flattening it out to a single level in the process. 
The specific use case is I wanted to copy my music from my collection to the USB drive for my car,
which has a limit of 255 files in a folder. There's an optional third argument if you want to exclude
top or second-level folders; just build a JSON file, and pass the file location
as the third argument. 

Exmaple usage:

music_to_usb.py '/Volumes/HDD/Music' '/Volumes/CAR_USB'
music_to_usb.py '/Volumes/HDD/Music' '/Volumes/CAR_USB' 'folders_to_skip.json'

In the JSON file, if you want to exclude second-level folders, just include
them as an array as the parameter of the top-level folder; the top-level folder will not be skipped,
only the specified subfolders. If you want the whole top-level folder skipped, the value
should be false.

skip_folder_json_template:

{"Folders : 
    { 
        "Top Level Folder 1": false,
        "Only Skip Second Level Folders" : [ "Sub Folder 1", "Sub Folder 2" ],
        "Only One Subfolder" : ['Sub Folder 1" ],
        "Whole Folder" : false
    }
}
'''

import os
import sys
import json
import re
import shutil

if (len(sys.argv) < 3):
    print('You need to provide a destination and source folder')
    exit()

regex_hidden_folder = '^\..*'
folder_to_copy_from = sys.argv[1]
folder_to_copy_to = sys.argv[2]

def true_false():
    while True:
        prompt = 'Make sure ' + folder_to_copy_to + ' is empty, otherwise it will fail if there are folders with the same name. To continue, type "Yes" > '
        answer = input(prompt).lower()
        if answer == 'yes':
            return True
        else:
            return False

if not true_false():
    exit()

def make_destination_folder(destination, source, folder_count):
    os.makedirs(destination + '/' + source + '-' + str(folder_count) )

def copy_folder(source):
    copy_from = folder_to_copy_from + '/' + source
    folder_count = 0
    file_count = 0
    for root, dirs, files in os.walk(copy_from):
        for f in files:
            # Hidden files
            if f[0] == '.':
                continue
            # If not audio files that can be played in most cars
            if f[-3:] != 'mp3' and f[-3:] != 'm4a':
                continue
            if source in folders_with_ignored_subfolder.keys():
                # Get the folder of the file we're working in
                current_folder = root.split(source+'/')[1]
                if current_folder in folders_with_ignored_subfolder[source]:
                    continue
            #If we're just starting out, we need to create our destination folder
            if file_count == 0:
                folder_count += 1
                make_destination_folder(folder_to_copy_to, source, folder_count)
            # My car only recognizes 255 files in a folder, so we have to start new folders after we've reached the limit
            if file_count == 255:
                folder_count += 1
                make_destination_folder(folder_to_copy_to, source, folder_count)
                file_count = 0
            file_count += 1
            old_path = root + '/' + f
            new_path = folder_to_copy_to + '/' + source + '-' + str(folder_count) + '/' + f
            shutil.copy2(old_path,new_path)

if ( len(sys.argv) == 4):
    folders_to_ignore = sys.argv[3]
else:
    folders_to_ignore = False

if not (os.path.isdir(folder_to_copy_from) and os.path.isdir(folder_to_copy_to) ):
    print('Please check your source and destination folders to make sure they exist.')
    exit()

if folders_to_ignore:
    if os.path.isfile(folders_to_ignore):
        with open(folders_to_ignore, 'r') as json_file:
            folder_list = json.load(json_file)['Folders']
            folders_to_ignore = []
            folders_with_ignored_subfolder = {}
            for folder, has_subfolder in folder_list.items():
                if not has_subfolder:
                    folders_to_ignore.append(folder)
                else:
                    folders_with_ignored_subfolder[folder] = []
                    for subfolder in has_subfolder:                    
                        folders_with_ignored_subfolder[folder].append(subfolder)

folders_to_copy = os.listdir(folder_to_copy_from)

for folder in folders_to_copy:
    if not folders_to_ignore:
        if not re.match(regex_hidden_folder, folder):
            copy_folder(folder)
    else:
        # If we need to ignore the folder, or it's a system folder
        if (folder in folders_to_ignore or re.match(regex_hidden_folder, folder) ):
            continue
        else:
            copy_folder(folder)