generates simple .m3u playlists

playlists.py

####
# Generates an .m3u playlist of all desired files
# Reed Jones 07/04/18
#
# python playlists.py
# >> generates .m3u containing all .mp4's in current directory by default
# >> saves as playlist.m3u
#
# python playlists.py --name my-great-playlist --extension .mp3 --path "C:\music\album"
# >> generates .m3u playlist containing all .mp4's and .mp3's in C:\music\album
# >> saves as C:\music\album\my-greate-playlist.m3u
####

from sys import argv
from os import listdir, getcwd
from os.path import isfile, join, splitext, abspath


# parses the passed in arguments into a useful dictionary
# eg: doSomething.py -t test -c one -c two three
# >> {'-t': ['test'], '-c': ['one', 'two', 'three']}
def getopts(argv):
    opts = {}
    index = 1
    while argv:
        if argv[0][0] == '-':
            options = []
            for n in range(1, len(argv)):
                index = n
                if argv[n][0] == '-':
                    break
                options.append(argv[n])
            if argv[0] in opts:
                opts[argv[0]] = opts[argv[0]] + options
            else:
                opts[argv[0]] = options
        argv = argv[index:]
    return opts


# checks if the given flag exists, and if not, sets a default
# if flag is a string, (such as '--extension') it will return all matching arguments
# as formatted in the above getOpts function, or the default value if none are found
# if flag is a list, it concats all matching arguments and returns that, or default
# with this, you can check for ['-ext', '--extension'] and combine all results into a
# useful list
def checkOpts(opts, flag, default=None):
    if isinstance(flag, str):
        return opts[flag] if flag in opts else default

    elif isinstance(flag, list):
        flags = []

        for f in flag:
            if f in opts:
                flags += opts[f]

        return flags if flags else default


# writes and formats an .m3u file containing all desired files
# and saves the playlist to the same directory as the files are in
def writeM3U(name, path, extensions):
    # opens new file in current directory
    with open(path + '/' + name + '.m3u', 'w+') as f:
        # m3u file header
        f.write('#EXTM3U\n\n')
        # list all files in current directory
        for file in listdir(path):
            # get file name/extension
            file_name, ext = splitext(file)
            # print(isfile(path + '/' + file))
            # check if file meets criteria
            if isfile(path + '/' + file) and ext in extensions:
                # writes filename to list
                f.write('#EXTINF ' + file_name + '\n')
                f.write(file + '\n\n')


def main():
    # parse argv
    opts = getopts(argv)

    # set desired filetypes
    accepted_filetypes = checkOpts(opts, ['-ext', '--extension'], ['.mp4'])

    # set desired playlist name, if multiple are given, it joins them
    desired_name = '_'.join(checkOpts(opts, ['-n', '--name'], 'playlist'))

    # set path, defaults to current working directory
    path = ''.join(checkOpts(opts, ['-p', '--path'], getcwd()))

    # writes and formats .m3u file
    writeM3U(desired_name, path, accepted_filetypes)


#  run program
if __name__ == "__main__":
    main()