Create a valid podcast RSS feed from a base URL and a list of files.

feedgen.py

#!/usr/bin/env python3

'''
Author: Yotam Gingold <yotam (strudel) yotamgingold.com>
License: Public Domain [CC0](http://creativecommons.org/publicdomain/zero/1.0/)
On GitHub as a gist: https://gist.github.com/yig/4784a86c1343d2bed789dd243ce980fc
'''

'''
Example:

$ python3 feedgen.py -o feed.xml "https://www.website.com/secretpodcast/" file1.m4a file2.mp3 ...
$ scp feed.xml file1.m4a file2.mp3 ... website.com:www/secretpodcast/

In your podcast app, add the feed: https://www.website.com/secretpodcast/feed.xml
'''

from pathlib import Path
import datetime
import hashlib

## Podcast feed requirements:
##     https://podcasters.apple.com/support/823-podcast-requirements
##     https://help.apple.com/itc/podcasts_connect/#/itcb54353390
## Example: https://help.apple.com/itc/podcasts_connect/#/itcbaf351599

HEADER = '''<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" xmlns:content="http://purl.org/rss/1.0/modules/content/">
  <channel>
    <title>{title}</title>
    <language>en-us</language>
    <description>
      {description}
    </description>
    <itunes:type>serial</itunes:type>
    <itunes:image
      href="https://applehosted.podcasts.apple.com/hiking_treks/artwork.png"
    />
    <itunes:category text="Sports">
      <itunes:category text="Wilderness"/>
    </itunes:category>
    <itunes:explicit>false</itunes:explicit>
'''

ITEM = '''
    <item>
      <itunes:episodeType>full</itunes:episodeType>
      <itunes:season>{season}</itunes:season>
      <itunes:episode>{episode}</itunes:episode>
      <title>{title}</title>
      <description>
        {title}
      </description>
      <enclosure
        length="{bytes}" 
        type="audio/x-m4a" 
        url="{URL}"
      />
      <guid>{GUID}</guid>
      <pubDate>{date}</pubDate>
      <itunes:explicit>false</itunes:explicit>
    </item>
'''

FOOTER = '''
  </channel>
</rss>
'''

def ItemFromPath( URL, season, episode, path ):
    ## Convert to a pathlib Path for convenience.
    path = Path(path)
    stat = path.stat()
    
    title = path.stem
    bytes = stat.st_size
    
    mtime = stat.st_mtime
    ## RSS pubDate is defined by RFC822
    ## https://stackoverflow.com/questions/12270531/how-to-format-pubdate-with-python
    date = datetime.datetime.fromtimestamp(mtime).strftime("%a, %d %b %Y %H:%M:%S %z")
    
    GUID = hashlib.sha256( path.name.encode('utf-8') ).hexdigest()
    
    URL = URL.rstrip('/') + '/' + path.name
    
    return ITEM.format( **locals() )

def FeedFromPaths( url, paths, season = 1, title = 'My Podcast', description = 'My Podcast Description' ):
    
    items = [ ItemFromPath( url, season, i+1, path, ) for i, path in enumerate( sorted( paths ) ) ]
    return HEADER.format( title = title, description = description ) + ''.join( items ) + FOOTER

if __name__ == '__main__':
    import argparse
    parser = argparse.ArgumentParser( description = 'Generate a podcast feed from some files.' )
    parser.add_argument( 'URL', help = 'The base URL of the podcast.' )
    parser.add_argument( 'files', nargs='*', help = 'A list of audio files.' )
    parser.add_argument( '--season', type = int, default = 1, help = 'The season of the podcast.' )
    parser.add_argument( '--title', default = 'My Podcast', help = 'The title of the podcast.' )
    parser.add_argument( '--description', default = 'My Podcast Description', help = 'A description of the podcast.' )
    parser.add_argument( '-o', '--output', default = None, help = 'A file to save the podcast into. By default, prints to stdout.' )
    args = parser.parse_args()
    
    feed = FeedFromPaths( args.URL, args.files, season = args.season, title = args.title, description = args.description )
    print( feed, file = open( args.output, 'w' ) if args.output is not None else None )
    
    print( f"In your podcast app, add the feed: {args.URL.rstrip('/')}/feed.xml" )