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Description:

podcastdownloader 0.8.1

Podcast Downloader

The Python module designed for downloading files from given RSS feeds, particularly targeted at podcasts.
It does not use any sort of database but requires a configuration file.
The script is intended to be run periodically. Upon starting, it analyzes the directory where it previously stored downloaded files.
It then compares these files with those listed in the RSS feed, identifying any missing ones and downloading them.
The files searched by default are mp3.
The result of using the example below, on empty directories, will be:
dplocki@ghost-wheel:~$ python -m podcast_downloader
[2024-04-08 21:19:10] Loading configuration (from file: "~/.podcast_downloader_config.json")
[2024-04-08 21:19:15] Checking "The Skeptic Guide"
[2024-04-08 21:19:15] Last downloaded file "<none>"
[2024-04-08 21:19:15] The Skeptic Guide: Downloading file: "https://traffic.libsyn.com/secure/skepticsguide/skepticast2024-04-06.mp3" saved as "skepticast2024-04-06.mp3"
[2024-04-08 21:19:41] Checking "The Real Python Podcast"
[2024-04-08 21:19:41] Last downloaded file "<none>"
[2024-04-08 21:19:41] The Real Python Podcast: Downloading file: "https://chtbl.com/track/92DB94/files.realpython.com/podcasts/RPP_E199_03_Calvin.eef1db4d6679.mp3" saved as "[20240405] rpp_e199_03_calvin.eef1db4d6679.mp3"
[2024-04-08 21:20:04] Finished

The result:
dplocki@ghost-wheel:~$ tree podcasts/
podcasts/
├── RealPython
│ └── [20240405] rpp_e199_03_calvin.eef1db4d6679.mp3
└── SGTTU
└── skepticast2024-04-06.mp3

2 directories, 2 files

Setup
Installation from PyPI:
pip install podcast_downloader

Running the script
The script requires configuration file in order to work.
After installation, the script can be run as any Python module:
python -m podcast_downloader

It is also possible to run the script with given configuration file:
python -m podcast_downloader --config my_config.json

Configuration
An example of configuration file
{
"if_directory_empty": "download_from_4_days",
"podcasts": [
{
"name": "The Skeptic Guide",
"rss_link": "https://feed.theskepticsguide.org/feed/rss.aspx",
"path": "~/podcasts/SGTTU"
},
{
"rss_link": "https://realpython.com/podcasts/rpp/feed",
"path": "~/podcasts/RealPython",
"file_name_template": "[%publish_date%] %file_name%.%file_extension%"
}
]
}

The configuration file
By default the configuration file is placed in home directory. It's file name is: .podcast_downloader_config.json.
The config file is format in JSON. The expected encoding is utf-8.
The path to configuration file can be specified by script argument.
The settings hierarchy
The script replaces default values by those read from configuration file.
Those will be overload by values given from command line.
command line parameters > configuration file > default values

The main options

Property
Type
Required?
Default
Note

downloads_limit
number
no
infinity

if_directory_empty
string
no
download_last
See In case of empty directory

podcast_extensions
key-value
no
{".mp3": "audio/mpeg"}
See File types filter

podcasts
subsection
yes
[]
See Podcasts sub category

http_headers
key-value
no
{"User-Agent": "podcast-downloader"}
See HTTP request headers

fill_up_gaps
boolean
no
false
See Download files from gaps

download_delay
number
no
0
See Download delay

Podcasts sub category
The podcasts segment is the part of configuration file where you provide the array of objects with fallowing content:

Property
Type
Required
Default
Note

name
string
yes
-
The name of channel (use in logger)

rss_link
string
yes
-
The URL of RSS feed

path
string
yes
-
The path to directory, where podcast are stored, will be downloaded

file_name_template
string
no
%file_name%.%file_extension%
The template for the downloaded files, see File name template

disable
boolean
no
false
This podcast will be ignored

podcast_extensions
key-value
no
{".mp3": "audio/mpeg"}
The file filter

if_directory_empty
string
no
download_last
See In case of empty directory

require_date
boolean
no
false
Deprecated Is date of podcast should be added into name of file - use the file_name_template: [%publish_date%] %file_name%.%file_extension%"

http_headers
key-value
no
{"User-Agent": "podcast-downloader"}
See HTTP request headers

fill_up_gaps
boolean
no
false
See Download files from gaps

HTTP request headers
Some servers may not like how the urllib is presenting itself to them (the HTTP User-Agent header). This may lead into problems like: urllib.error.HTTPError: HTTP Error 403: Forbidden. That is why, there is a possibility for the script to pose as something else: by specifying the HTTP headers during downloading files.
Use the http_headers option in the configuration file. The value should be a dictionary object where each header is presented as a key-value pair. The key being the header title and the value being the header value.
By default the value is: {"User-Agent": "podcast-downloader"}. Providing anything else for http_headers will override all the default values (they do not merge).
On other hand in the podcast sub-configuration, the http_headers will be merged with the global http_headers. In case of a conflict (same key name), the vale from podcast sub-configuration will override the global one.
Example:
{
"http_headers": {
"User-Agent": "podcast-downloader"

},
"podcasts": [
{
"name": "Unua Podcast",
"rss_link": "http://www.unuapodcast.org/feed.rss",
"path": "~/podcasts/unua_podcast",
"https_headers": {
"User-Agent": "Mozilla/5.0"
}
},
{
"name": "Dua Podcast",
"rss_link": "http://www.duapodcast.org/feed.rss",
"path": "~/podcasts/dua_podcast",
"https_headers": {
"Authorization": "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ=="
}
}
]
}

In this example, the Unua Podcast will be download just with the header: User-Agent: Mozilla/5.0, and the Dua Podcast with: User-Agent: podcast-downloader and Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==.
Download delay
When you had a lot of files to download from a single server, it may be better to set up the small delay between downloads to avoid being recognized as an attacker by the server. In the script there is an option called download_delay, which represents the number of seconds the script will wait between downloads.
The default value is 0.
Notes:

this delay applies per podcast, not between two different podcasts
the value can be provided as script argument

Script arguments
The script accepts following command line arguments:

Short version
Long name
Parameter
Default
Note

--config
string
~/.podcast_downloader_config.json
The placement of the configuration file

--downloads_limit
number
infinity
The maximum number of downloaded mp3 files

--if_directory_empty
string
download_last
The general approach on empty directory

--download_delay
number
0
The waiting time (seconds) between downloads

File name template
Use to adjust the file name after downloading.
Default value (the %file_name%.%file_extension%) will simple save up the file as it was uploaded by original creator. The file name and its extension is based on the link to podcast file.
Template values:

Name
Notes

%file_name%
The file name from the link, without extension

%file_extension%
The extension for the file, from link

%publish_date%
The publish date of the RSS entry

%title%
The title of the RSS entry

Non-default the publish_date
The %publish_date% by default gives result in format YEARMMDD. In order to change it you can provide the new one after the colon (the : character). The script respect the codes of the 1989 C standard, but the percent sign (%) must be replaced by dollar sign ($). This is because of my unfortunate decision to use the percent character as marker of the code.

The standard code
The script code
Notes

%Y%m%d
$Y$m$d
The default value of the %publish_date%

%A
$A
Adds the weekday (local language settings)

%x
$x
The local date represent. Warning: in some settings, the / is used here, so it may caused problem in the file name

Examples

[%publish_date%] %file_name%.%file_extension%
[%publish_date%] %title%.%file_extension%

File types filter
Podcasts are mostly stored as *.mp3 files. By default Podcast Downloader looks just for them, ignoring all others types.
If your podcast supports other types of media files, you can specified the file filters. Provide the extension of the file (like .mp3) and type of link in RSS feed itself (for mp3 it is audio/mpeg).
If you don't know the type of the file, you can look for it in the RSS file. Seek for enclosure tags, should looks like this:
<enclosure url="https://www.vidocast.url/podcast/episode23.m4a"
length="14527149"
type="audio/x-m4a" />

Note: the dot on the file extension is require.
Example
"podcast_extensions": {
".mp3": "audio/mpeg",
".m4a": "audio/x-m4a"
}

In case of empty directory
If a directory for podcast is empty, the script needs to know what to do. Due to lack of database, you can:

download all episodes from feed
download only the last episode
download last n episodes
download all new episode from last n days
download all new episode since day after, the last episode should appear

Default behavior is: download_last
Download all from feed
The script will download all episodes from the feed.
Set by download_all_from_feed.
Download last
The script will download only the last episode from the feed.
It is also default approach of the script.
Set by download_last.
Download last n episodes
The script will download exactly the given number of episodes from the feed.
Set by download_last_n_episodes. The n must be replaced by a number of episodes, which you wanted to have downloaded. For example: download_last_5_episodes means that five most recent episodes will be downloaded.
Download all from n days
The script will download all episodes which appear in recent n days. It can be use when you are downloading on regular schedule.
The n number is given within the setup value: download_from_n_days. For example: download_from_3_days means download all episodes from last 3 days.
Download all episode since last excepted
The script will download all episodes which appear after the day of release of last episode.
The n number is the day of the normal episode.
You can provide here week days as word (size of the letters is ignored)

Full week day
Shorten name

Monday
Mon

Tuesday
Tues

Wednesday
Weds

Thursday
Thurs

Friday
Fri

Saturday
Sat

Sunday
Sun

You can provide the number, it will means the day of the month. The script accepts only number from 1 to 28.
Set by download_from_.
Examples:

Example value
Meaning

download_from_monday
New episodes appear in Monday. The script will download all episodes since last Tuesday (including it)

download_from_Fri
New episodes appear in Friday. The script will download all episodes since last Saturday (including it)

download_from_12
New episodes appear each 12th of month. The script will download all episodes since 13 month before

Download files from gaps
The script recognizes the stream of downloaded files (based on the feed data). By default, the last downloaded file (according to the feed) marks the start of downloading. In case of gaps, situation where there are missing files before the last downloaded one, the script will ignore them by default. However, there is a possibility to change this behavior to download all missing files between already downloaded ones. To enable this, you need to set the fill_up_gaps value to true. It's important to note that the script will not download files before the first one (according to the feed), the most earlier episode.
Default value: false.
The analyze of the RSS feed
The script looks through all the items nodes in RSS file. The item node can contain the enclosure node. Those nodes are used to passing the files. According to the convention the single item should contain only one enclosure, but script (as the library used under it) can handle the multiple files attached into podcast item.
Converting the OPML
The OPML files can be converted into configuration. The output file needs to be adjusted (missing the path).
import json
import sys
import xml.etree.ElementTree as ET

def build_podcast(node_rss):
return {
"name": node_rss.attrib["title"],
"rss_link": node_rss.attrib["xmlUrl"],
"path": "",
}

tree = ET.parse(sys.argv[1])
podcasts = list(map(build_podcast, tree.findall("body/outline[@type='rss']")))
result = json.dumps({"podcasts": podcasts}, sort_keys=True, indent=4)

print(result)

Example of usage (after saving it as opml_converter.py):
python opml_converter.py example.opml > podcast_downloader_config.json