Added folder to save files

[arsaboo]

Currently, fmdpy saves everything in the root folder, making importing difficult (for example, beets only imports files in folders). Added an artist folder under which files will be saved (we can even use album, if you prefer that). This is the same format that is used by other similar programs (e.g., deemix).

[arsaboo]

@Liupold not sure how to handle the file path. There are a few errors that I am not sure how to handle. Can you take a look into this...thanks!

[Liupold]

I think a better way of doing this is using the config file. default_directoy and output_file_name can support the string replacement supported by player_cmd (we can add more if need be). But before the folder / file is created a safe check must be performed on the path as some operating system doesn't support some folder / file names. This will provide what you want + this will also preserve the current behaviour. What do you think ?

[Liupold]

Refer to:
https://github.com/yt-dlp/yt-dlp/blob/0bea4fd8072c1421ab3a94f0601ddef9df14f133/yt_dlp/utils.py#L642-L688
and
https://github.com/yt-dlp/yt-dlp/blob/0bea4fd8072c1421ab3a94f0601ddef9df14f133/yt_dlp/utils.py#L691-L711

[Liupold]

This can be used:

import os, re

def sanitize_filename(s, restricted=False):
    if s == '':
        return ''

    def replace_insane(char):
        if char == '\n':
            return '_ '
        elif char == '?' or ord(char) < 32 or ord(char) == 127:
            return ''
        elif char == '"':
            return '' if restricted else '\''
        elif char == ':':
            return '___-' if restricted else '_ _-'
        elif char in '\\/|*<>':
            return '__'
        if restricted and (char in '!&\'()[]{}$;`^,#' or char.isspace() or ord(char) > 127):
            return '__'
        return char

    s = re.sub(r'[0-9]+(?::[0-9]+)+',
            lambda m: m.group(0).replace(':', '_'), s) # Handle timestamps
    result = ''.join(map(replace_insane, s))

    # Remove repeated substitute chars
    result = re.sub('(_.)(?:(?=\\1)..)+', r'\1', result)
    STRIP_RE = '(?:_.|[ _-])*'

    # Remove substitute chars from start/end
    result = re.sub(f'^_.{STRIP_RE}|{STRIP_RE}_.$', '', result)

    while '__' in result:
        result = result.replace('__', '_')
    result = result.strip('_')
    # Common case of "Foreign band name - English song title"
    if restricted and result.startswith('-_'):
        result = result[2:]
    if result.startswith('-'):
        result = '_' + result[len('-'):]
    result = result.lstrip('.')
    if not result:
        result = '_'
    return result

[arsaboo]

The output_file_name option sounds great and should work for everyone. You clearly have thought more about this, so I am going to close this PR and hope that you can incorporate this feature..thanks!

[Liupold]

This feature will be available from version 0.6.