API

YouTube Object

class pytube.YouTube(url: str, on_progress_callback: Optional[Callable[[Any, bytes, int], None]] = None, on_complete_callback: Optional[Callable[[Any, Optional[str]], None]] = None, proxies: Dict[str, str] = None, use_oauth: bool = False, allow_oauth_cache: bool = True)[source]

Core developer interface for pytube.

author

Get the video author. :rtype: str

bypass_age_gate()[source]

Attempt to update the vid_info by bypassing the age gate.

caption_tracks

Get a list of Caption.

Return type:List[Caption]
captions

Interface to query caption tracks.

Return type:CaptionQuery.
channel_id

Get the video poster’s channel id.

Return type:str
channel_url

Construct the channel url for the video’s poster from the channel id.

Return type:str
check_availability()[source]

Check whether the video is available.

Raises different exceptions based on why the video is unavailable, otherwise does nothing.

description

Get the video description.

Return type:str
fmt_streams

Returns a list of streams if they have been initialized.

If the streams have not been initialized, finds all relevant streams and initializes them.

static from_id(video_id: str) → pytube.__main__.YouTube[source]

Construct a YouTube object from a video id.

Parameters:video_id (str) – The video id of the YouTube video.
Return type:YouTube
keywords

Get the video keywords.

Return type:List[str]
length

Get the video length in seconds.

Return type:int
metadata

Get the metadata for the video.

Return type:YouTubeMetadata
publish_date

Get the publish date.

Return type:datetime
rating

Get the video average rating.

Return type:float
register_on_complete_callback(func: Callable[[Any, Optional[str]], None])[source]

Register a download complete callback function post initialization.

Parameters:func (callable) – A callback function that takes stream and file_path.
Return type:None
register_on_progress_callback(func: Callable[[Any, bytes, int], None])[source]

Register a download progress callback function post initialization.

Parameters:func (callable) –
A callback function that takes stream, chunk,
and bytes_remaining as parameters.
Return type:None
streaming_data

Return streamingData from video info.

streams

Interface to query both adaptive (DASH) and progressive streams.

Return type:StreamQuery.
thumbnail_url

Get the thumbnail url image.

Return type:str
title

Get the video title.

Return type:str
vid_info

Parse the raw vid info and return the parsed result.

Return type:Dict[Any, Any]
views

Get the number of the times the video has been viewed.

Return type:int

Playlist Object

class pytube.contrib.playlist.Playlist(url: str, proxies: Optional[Dict[str, str]] = None)[source]

Load a YouTube playlist with URL

count(value) → integer -- return number of occurrences of value
html

Get the playlist page html.

Return type:str
index(value[, start[, stop]]) → integer -- return first index of value.

Raises ValueError if the value is not present.

Supporting start and stop arguments is optional, but recommended.

initial_data

Extract the initial data from the playlist page html.

Return type:dict
last_updated

Extract the date that the playlist was last updated.

For some playlists, this will be a specific date, which is returned as a datetime object. For other playlists, this is an estimate such as “1 week ago”. Due to the fact that this value is returned as a string, pytube does a best-effort parsing where possible, and returns the raw string where it is not possible.

Returns:Date of last playlist update where possible, else the string provided
Return type:datetime.date
length

Extract the number of videos in the playlist.

Returns:Playlist video count
Return type:int
owner

Extract the owner of the playlist.

Returns:Playlist owner name.
Return type:str
owner_id

Extract the channel_id of the owner of the playlist.

Returns:Playlist owner’s channel ID.
Return type:str
owner_url

Create the channel url of the owner of the playlist.

Returns:Playlist owner’s channel url.
Return type:str
playlist_id

Get the playlist id.

Return type:str
playlist_url

Get the base playlist url.

Return type:str
sidebar_info

Extract the sidebar info from the playlist page html.

Return type:dict
title

Extract playlist title

Returns:playlist title (name)
Return type:Optional[str]
trimmed(video_id: str) → Iterable[str][source]

Retrieve a list of YouTube video URLs trimmed at the given video ID

i.e. if the playlist has video IDs 1,2,3,4 calling trimmed(3) returns [1,2] :type video_id: str

video ID to trim the returned list of playlist URLs at
Return type:List[str]
Returns:List of video URLs from the playlist trimmed at the given ID
url_generator()[source]

Generator that yields video URLs.

Yields:Video URLs
video_urls

Complete links of all the videos in playlist

Return type:List[str]
Returns:List of video URLs
videos

Yields YouTube objects of videos in this playlist

Return type:List[YouTube]
Returns:List of YouTube
views

Extract view count for playlist.

Returns:Playlist view count
Return type:int
yt_api_key

Extract the INNERTUBE_API_KEY from the playlist ytcfg.

Return type:str
ytcfg

Extract the ytcfg from the playlist page html.

Return type:dict

Channel Object

class pytube.contrib.channel.Channel(url: str, proxies: Optional[Dict[str, str]] = None)[source]
about_html

Get the html for the /about page.

Currently unused for any functionality.

Return type:str
channel_id

Get the ID of the YouTube channel.

This will return the underlying ID, not the vanity URL.

Return type:str
channel_name

Get the name of the YouTube channel.

Return type:str
community_html

Get the html for the /community page.

Currently unused for any functionality.

Return type:str
count(value) → integer -- return number of occurrences of value
featured_channels_html

Get the html for the /channels page.

Currently unused for any functionality.

Return type:str
html

Get the html for the /videos page.

Return type:str
index(value[, start[, stop]]) → integer -- return first index of value.

Raises ValueError if the value is not present.

Supporting start and stop arguments is optional, but recommended.

initial_data

Extract the initial data from the playlist page html.

Return type:dict
last_updated

Extract the date that the playlist was last updated.

For some playlists, this will be a specific date, which is returned as a datetime object. For other playlists, this is an estimate such as “1 week ago”. Due to the fact that this value is returned as a string, pytube does a best-effort parsing where possible, and returns the raw string where it is not possible.

Returns:Date of last playlist update where possible, else the string provided
Return type:datetime.date
length

Extract the number of videos in the playlist.

Returns:Playlist video count
Return type:int
owner

Extract the owner of the playlist.

Returns:Playlist owner name.
Return type:str
owner_id

Extract the channel_id of the owner of the playlist.

Returns:Playlist owner’s channel ID.
Return type:str
owner_url

Create the channel url of the owner of the playlist.

Returns:Playlist owner’s channel url.
Return type:str
playlist_id

Get the playlist id.

Return type:str
playlist_url

Get the base playlist url.

Return type:str
playlists_html

Get the html for the /playlists page.

Currently unused for any functionality.

Return type:str
sidebar_info

Extract the sidebar info from the playlist page html.

Return type:dict
title

Extract playlist title

Returns:playlist title (name)
Return type:Optional[str]
trimmed(video_id: str) → Iterable[str]

Retrieve a list of YouTube video URLs trimmed at the given video ID

i.e. if the playlist has video IDs 1,2,3,4 calling trimmed(3) returns [1,2] :type video_id: str

video ID to trim the returned list of playlist URLs at
Return type:List[str]
Returns:List of video URLs from the playlist trimmed at the given ID
url_generator()

Generator that yields video URLs.

Yields:Video URLs
vanity_url

Get the vanity URL of the YouTube channel.

Returns None if it doesn’t exist.

Return type:str
video_urls

Complete links of all the videos in playlist

Return type:List[str]
Returns:List of video URLs
videos

Yields YouTube objects of videos in this playlist

Return type:List[YouTube]
Returns:List of YouTube
views

Extract view count for playlist.

Returns:Playlist view count
Return type:int
yt_api_key

Extract the INNERTUBE_API_KEY from the playlist ytcfg.

Return type:str
ytcfg

Extract the ytcfg from the playlist page html.

Return type:dict

Stream Object

class pytube.Stream(stream: Dict[KT, VT], monostate: pytube.monostate.Monostate)[source]

Container for stream manifest data.

default_filename

Generate filename based on the video title.

Return type:str
Returns:An os file system compatible filename.
download(output_path: Optional[str] = None, filename: Optional[str] = None, filename_prefix: Optional[str] = None, skip_existing: bool = True, timeout: Optional[int] = None, max_retries: Optional[int] = 0) → str[source]

Write the media stream to disk.

Parameters:
  • output_path (str or None) – (optional) Output path for writing media file. If one is not specified, defaults to the current working directory.
  • filename (str or None) – (optional) Output filename (stem only) for writing media file. If one is not specified, the default filename is used.
  • filename_prefix (str or None) – (optional) A string that will be prepended to the filename. For example a number in a playlist or the name of a series. If one is not specified, nothing will be prepended This is separate from filename so you can use the default filename but still add a prefix.
  • skip_existing (bool) – (optional) Skip existing files, defaults to True
  • timeout (int) – (optional) Request timeout length in seconds. Uses system default.
  • max_retries (int) – (optional) Number of retries to attempt after socket timeout. Defaults to 0.
Returns:

Path to the saved video
Return type:

str
filesize

File size of the media stream in bytes.

Return type:int
Returns:Filesize (in bytes) of the stream.
filesize_approx

Get approximate filesize of the video

Falls back to HTTP call if there is not sufficient information to approximate

Return type:int
Returns:size of video in bytes
filesize_gb

File size of the media stream in gigabytes.

Return type:float
Returns:Rounded filesize (in gigabytes) of the stream.
filesize_kb

File size of the media stream in kilobytes.

Return type:float
Returns:Rounded filesize (in kilobytes) of the stream.
filesize_mb

File size of the media stream in megabytes.

Return type:float
Returns:Rounded filesize (in megabytes) of the stream.
includes_audio_track

Whether the stream only contains audio.

Return type:bool
includes_video_track

Whether the stream only contains video.

Return type:bool
is_adaptive

Whether the stream is DASH.

Return type:bool
is_progressive

Whether the stream is progressive.

Return type:bool
on_complete(file_path: Optional[str])[source]

On download complete handler function.

Parameters:file_path (str) – The file handle where the media is being written to.
Return type:None
on_progress(chunk: bytes, file_handler: BinaryIO, bytes_remaining: int)[source]

On progress callback function.

This function writes the binary data to the file, then checks if an additional callback is defined in the monostate. This is exposed to allow things like displaying a progress bar.

Parameters:
  • chunk (bytes) – Segment of media file binary data, not yet written to disk.
  • file_handler (io.BufferedWriter) – The file handle where the media is being written to.
  • bytes_remaining (int) – The delta between the total file size in bytes and amount already downloaded.
Return type:

None
parse_codecs() → Tuple[Optional[str], Optional[str]][source]

Get the video/audio codecs from list of codecs.

Parse a variable length sized list of codecs and returns a constant two element tuple, with the video codec as the first element and audio as the second. Returns None if one is not available (adaptive only).

Return type:tuple
Returns:A two element tuple with audio and video codecs.
stream_to_buffer(buffer: BinaryIO) → None[source]

Write the media stream to buffer

Return type:io.BytesIO buffer
title

Get title of video

Return type:str
Returns:Youtube video title

StreamQuery Object

class pytube.query.StreamQuery(fmt_streams)[source]

Interface for querying the available media streams.

all() → List[pytube.streams.Stream][source]

Get all the results represented by this query as a list.

Return type:list
asc() → pytube.query.StreamQuery[source]

Sort streams in ascending order.

Return type:StreamQuery
count(value: Optional[str] = None) → int[source]

Get the count of items in the list.

Return type:int
desc() → pytube.query.StreamQuery[source]

Sort streams in descending order.

Return type:StreamQuery
filter(fps=None, res=None, resolution=None, mime_type=None, type=None, subtype=None, file_extension=None, abr=None, bitrate=None, video_codec=None, audio_codec=None, only_audio=None, only_video=None, progressive=None, adaptive=None, is_dash=None, custom_filter_functions=None)[source]

Apply the given filtering criterion.

Parameters:
  • fps (int or None) – (optional) The frames per second.
  • resolution (str or None) – (optional) Alias to res.
  • res (str or None) – (optional) The video resolution.
  • mime_type (str or None) – (optional) Two-part identifier for file formats and format contents composed of a “type”, a “subtype”.
  • type (str or None) – (optional) Type part of the mime_type (e.g.: audio, video).
  • subtype (str or None) – (optional) Sub-type part of the mime_type (e.g.: mp4, mov).
  • file_extension (str or None) – (optional) Alias to sub_type.
  • abr (str or None) – (optional) Average bitrate (ABR) refers to the average amount of data transferred per unit of time (e.g.: 64kbps, 192kbps).
  • bitrate (str or None) – (optional) Alias to abr.
  • video_codec (str or None) – (optional) Video compression format.
  • audio_codec (str or None) – (optional) Audio compression format.
  • progressive (bool) – Excludes adaptive streams (one file contains both audio and video tracks).
  • adaptive (bool) – Excludes progressive streams (audio and video are on separate tracks).
  • is_dash (bool) – Include/exclude dash streams.
  • only_audio (bool) – Excludes streams with video tracks.
  • only_video (bool) – Excludes streams with audio tracks.
  • custom_filter_functions (list or None) – (optional) Interface for defining complex filters without subclassing.
first() → Optional[pytube.streams.Stream][source]

Get the first Stream in the results.

Return type:Stream or None
Returns:the first result of this query or None if the result doesn’t contain any streams.
get_audio_only(subtype: str = 'mp4') → Optional[pytube.streams.Stream][source]

Get highest bitrate audio stream for given codec (defaults to mp4)

Parameters:subtype (str) – Audio subtype, defaults to mp4
Return type:Stream or None
Returns:The Stream matching the given itag or None if not found.
get_by_itag(itag: int) → Optional[pytube.streams.Stream][source]

Get the corresponding Stream for a given itag.

Parameters:itag (int) – YouTube format identifier code.
Return type:Stream or None
Returns:The Stream matching the given itag or None if not found.
get_by_resolution(resolution: str) → Optional[pytube.streams.Stream][source]

Get the corresponding Stream for a given resolution.

Stream must be a progressive mp4.

Parameters:resolution (str) – Video resolution i.e. “720p”, “480p”, “360p”, “240p”, “144p”
Return type:Stream or None
Returns:The Stream matching the given itag or None if not found.
get_highest_resolution() → Optional[pytube.streams.Stream][source]

Get highest resolution stream that is a progressive video.

Return type:Stream or None
Returns:The Stream matching the given itag or None if not found.
get_lowest_resolution() → Optional[pytube.streams.Stream][source]

Get lowest resolution stream that is a progressive mp4.

Return type:Stream or None
Returns:The Stream matching the given itag or None if not found.
index(value[, start[, stop]]) → integer -- return first index of value.

Raises ValueError if the value is not present.

Supporting start and stop arguments is optional, but recommended.

last()[source]

Get the last Stream in the results.

Return type:Stream or None
Returns:Return the last result of this query or None if the result doesn’t contain any streams.
order_by(attribute_name: str) → pytube.query.StreamQuery[source]

Apply a sort order. Filters out stream the do not have the attribute.

Parameters:attribute_name (str) – The name of the attribute to sort by.
otf(is_otf: bool = False) → pytube.query.StreamQuery[source]

Filter stream by OTF, useful if some streams have 404 URLs

Parameters:is_otf (bool) – Set to False to retrieve only non-OTF streams
Return type:StreamQuery
Returns:A StreamQuery object with otf filtered streams

Caption Object

class pytube.Caption(caption_track: Dict[KT, VT])[source]

Container for caption tracks.

download(title: str, srt: bool = True, output_path: Optional[str] = None, filename_prefix: Optional[str] = None) → str[source]

Write the media stream to disk.

Parameters:
  • title (str) – Output filename (stem only) for writing media file. If one is not specified, the default filename is used.
  • srt – Set to True to download srt, false to download xml. Defaults to True.

:type srt bool :param output_path:

(optional) Output path for writing media file. If one is not specified, defaults to the current working directory.
Parameters:filename_prefix (str or None) – (optional) A string that will be prepended to the filename. For example a number in a playlist or the name of a series. If one is not specified, nothing will be prepended This is separate from filename so you can use the default filename but still add a prefix.
Return type:str
static float_to_srt_time_format(d: float) → str[source]

Convert decimal durations into proper srt format.

Return type:str
Returns:SubRip Subtitle (str) formatted time duration.

float_to_srt_time_format(3.89) -> ‘00:00:03,890’

generate_srt_captions() → str[source]

Generate “SubRip Subtitle” captions.

Takes the xml captions from xml_captions() and recompiles them into the “SubRip Subtitle” format.

json_captions

Download and parse the json caption tracks.

xml_caption_to_srt(xml_captions: str) → str[source]

Convert xml caption tracks to “SubRip Subtitle (srt)”.

Parameters:xml_captions (str) – XML formatted caption tracks.
xml_captions

Download the xml caption tracks.

CaptionQuery Object

class pytube.query.CaptionQuery(captions: List[pytube.captions.Caption])[source]

Interface for querying the available captions.

all() → List[pytube.captions.Caption][source]

Get all the results represented by this query as a list.

Return type:list
get(k[, d]) → D[k] if k in D, else d. d defaults to None.
get_by_language_code(lang_code: str) → Optional[pytube.captions.Caption][source]

Get the Caption for a given lang_code.

Parameters:lang_code (str) – The code that identifies the caption language.
Return type:Caption or None
Returns:The Caption matching the given lang_code or None if it does not exist.
items() → a set-like object providing a view on D's items
keys() → a set-like object providing a view on D's keys
values() → an object providing a view on D's values

Search Object

class pytube.contrib.search.Search(query)[source]
completion_suggestions

Return query autocompletion suggestions for the query.

Return type:list
Returns:A list of autocomplete suggestions provided by YouTube for the query.
fetch_and_parse(continuation=None)[source]

Fetch from the innertube API and parse the results.

Parameters:continuation (str) – Continuation string for fetching results.
Return type:tuple
Returns:A tuple of a list of YouTube objects and a continuation string.
fetch_query(continuation=None)[source]

Fetch raw results from the innertube API.

Parameters:continuation (str) – Continuation string for fetching results.
Return type:dict
Returns:The raw json object returned by the innertube API.
get_next_results()[source]

Use the stored continuation string to fetch the next set of results.

This method does not return the results, but instead updates the results property.

results

Return search results.

On first call, will generate and return the first set of results. Additional results can be generated using .get_next_results().

Return type:list
Returns:A list of YouTube objects.

Extract

This module contains all non-cipher related data extraction logic.

pytube.extract.apply_descrambler(stream_data: Dict[KT, VT]) → None[source]

Apply various in-place transforms to YouTube’s media stream data.

Creates a list of dictionaries by string splitting on commas, then taking each list item, parsing it as a query string, converting it to a dict and unquoting the value.

Parameters:stream_data (dict) – Dictionary containing query string encoded values.

Example:

>>> d = {'foo': 'bar=1&var=test,em=5&t=url%20encoded'}
>>> apply_descrambler(d, 'foo')
>>> print(d)
{'foo': [{'bar': '1', 'var': 'test'}, {'em': '5', 't': 'url encoded'}]}
pytube.extract.apply_signature(stream_manifest: Dict[KT, VT], vid_info: Dict[KT, VT], js: str) → None[source]

Apply the decrypted signature to the stream manifest.

Parameters:
  • stream_manifest (dict) – Details of the media streams available.
  • js (str) – The contents of the base.js asset file.
pytube.extract.channel_name(url: str) → str[source]

Extract the channel_name or channel_id from a YouTube url.

This function supports the following patterns:

Parameters:url (str) – A YouTube url containing a channel name.
Return type:str
Returns:YouTube channel name.
pytube.extract.get_ytcfg(html: str) → str[source]

Get the entirety of the ytcfg object.

This is built over multiple pieces, so we have to find all matches and combine the dicts together.

Parameters:html (str) – The html contents of the watch page.
Return type:str
Returns:Substring of the html containing the encoded manifest data.
pytube.extract.get_ytplayer_config(html: str) → Any[source]

Get the YouTube player configuration data from the watch html.

Extract the ytplayer_config, which is json data embedded within the watch html and serves as the primary source of obtaining the stream manifest data.

Parameters:html (str) – The html contents of the watch page.
Return type:str
Returns:Substring of the html containing the encoded manifest data.
pytube.extract.get_ytplayer_js(html: str) → Any[source]

Get the YouTube player base JavaScript path.

:param str html
The html contents of the watch page.
Return type:str
Returns:Path to YouTube’s base.js file.
pytube.extract.initial_data(watch_html: str) → str[source]

Extract the ytInitialData json from the watch_html page.

This mostly contains metadata necessary for rendering the page on-load, such as video information, copyright notices, etc.

@param watch_html: Html of the watch page @return:

pytube.extract.initial_player_response(watch_html: str) → str[source]

Extract the ytInitialPlayerResponse json from the watch_html page.

This mostly contains metadata necessary for rendering the page on-load, such as video information, copyright notices, etc.

@param watch_html: Html of the watch page @return:

pytube.extract.is_age_restricted(watch_html: str) → bool[source]

Check if content is age restricted.

Parameters:watch_html (str) – The html contents of the watch page.
Return type:bool
Returns:Whether or not the content is age restricted.
pytube.extract.is_private(watch_html)[source]

Check if content is private.

Parameters:watch_html (str) – The html contents of the watch page.
Return type:bool
Returns:Whether or not the content is private.
pytube.extract.js_url(html: str) → str[source]

Get the base JavaScript url.

Construct the base JavaScript url, which contains the decipher “transforms”.

Parameters:html (str) – The html contents of the watch page.
pytube.extract.metadata(initial_data) → Optional[pytube.metadata.YouTubeMetadata][source]

Get the informational metadata for the video.

e.g.: [

{
‘Song’: ‘강남스타일(Gangnam Style)’, ‘Artist’: ‘PSY’, ‘Album’: ‘PSY SIX RULES Pt.1’, ‘Licensed to YouTube by’: ‘YG Entertainment Inc. […]’

}

]

Return type:YouTubeMetadata
pytube.extract.mime_type_codec(mime_type_codec: str) → Tuple[str, List[str]][source]

Parse the type data.

Breaks up the data in the type key of the manifest, which contains the mime type and codecs serialized together, and splits them into separate elements.

Example:

mime_type_codec(‘audio/webm; codecs=”opus”’) -> (‘audio/webm’, [‘opus’])

Parameters:mime_type_codec (str) – String containing mime type and codecs.
Return type:tuple
Returns:The mime type and a list of codecs.
pytube.extract.playability_status(watch_html: str) -> (<class 'str'>, <class 'str'>)[source]

Return the playability status and status explanation of a video.

For example, a video may have a status of LOGIN_REQUIRED, and an explanation of “This is a private video. Please sign in to verify that you may see it.”

This explanation is what gets incorporated into the media player overlay.

Parameters:watch_html (str) – The html contents of the watch page.
Return type:bool
Returns:Playability status and reason of the video.
pytube.extract.playlist_id(url: str) → str[source]

Extract the playlist_id from a YouTube url.

This function supports the following patterns:

  • https://youtube.com/playlist?list=playlist_id
  • https://youtube.com/watch?v=video_id&list=playlist_id
Parameters:url (str) – A YouTube url containing a playlist id.
Return type:str
Returns:YouTube playlist id.
pytube.extract.publish_date(watch_html: str)[source]

Extract publish date :param str watch_html:

The html contents of the watch page.
Return type:str
Returns:Publish date of the video.
pytube.extract.recording_available(watch_html)[source]

Check if live stream recording is available.

Parameters:watch_html (str) – The html contents of the watch page.
Return type:bool
Returns:Whether or not the content is private.
pytube.extract.video_id(url: str) → str[source]

Extract the video_id from a YouTube url.

This function supports the following patterns:

  • https://youtube.com/watch?v=video_id
  • https://youtube.com/embed/video_id
  • https://youtu.be/video_id
Parameters:url (str) – A YouTube url containing a video id.
Return type:str
Returns:YouTube video id.
pytube.extract.video_info_url(video_id: str, watch_url: str) → str[source]

Construct the video_info url.

Parameters:
  • video_id (str) – A YouTube video identifier.
  • watch_url (str) – A YouTube watch url.
Return type:

str
Returns:

https://youtube.com/get_video_info with necessary GET parameters.
pytube.extract.video_info_url_age_restricted(video_id: str, embed_html: str) → str[source]

Construct the video_info url.

Parameters:
  • video_id (str) – A YouTube video identifier.
  • embed_html (str) – The html contents of the embed page (for age restricted videos).
Return type:

str
Returns:

https://youtube.com/get_video_info with necessary GET parameters.

Cipher

This module contains all logic necessary to decipher the signature.

YouTube’s strategy to restrict downloading videos is to send a ciphered version of the signature to the client, along with the decryption algorithm obfuscated in JavaScript. For the clients to play the videos, JavaScript must take the ciphered version, cycle it through a series of “transform functions,” and then signs the media URL with the output.

This module is responsible for (1) finding and extracting those “transform functions” (2) maps them to Python equivalents and (3) taking the ciphered signature and decoding it.

pytube.cipher.get_initial_function_name(js: str) → str[source]

Extract the name of the function responsible for computing the signature. :param str js:

The contents of the base.js asset file.
Return type:str
Returns:Function name from regex match
pytube.cipher.get_throttling_function_array(js: str) → List[Any][source]

Extract the “c” array.

Parameters:js (str) – The contents of the base.js asset file.
Returns:The array of various integers, arrays, and functions.
pytube.cipher.get_throttling_function_code(js: str) → str[source]

Extract the raw code for the throttling function.

Parameters:js (str) – The contents of the base.js asset file.
Return type:str
Returns:The name of the function used to compute the throttling parameter.
pytube.cipher.get_throttling_function_name(js: str) → str[source]

Extract the name of the function that computes the throttling parameter.

Parameters:js (str) – The contents of the base.js asset file.
Return type:str
Returns:The name of the function used to compute the throttling parameter.
pytube.cipher.get_throttling_plan(js: str)[source]

Extract the “throttling plan”.

The “throttling plan” is a list of tuples used for calling functions in the c array. The first element of the tuple is the index of the function to call, and any remaining elements of the tuple are arguments to pass to that function.

Parameters:js (str) – The contents of the base.js asset file.
Returns:The full function code for computing the throttlign parameter.
pytube.cipher.get_transform_map(js: str, var: str) → Dict[KT, VT][source]

Build a transform function lookup.

Build a lookup table of obfuscated JavaScript function names to the Python equivalents.

Parameters:
  • js (str) – The contents of the base.js asset file.
  • var (str) – The obfuscated variable name that stores an object with all functions that descrambles the signature.
pytube.cipher.get_transform_object(js: str, var: str) → List[str][source]

Extract the “transform object”.

The “transform object” contains the function definitions referenced in the “transform plan”. The var argument is the obfuscated variable name which contains these functions, for example, given the function call DE.AJ(a,15) returned by the transform plan, “DE” would be the var.

Parameters:
  • js (str) – The contents of the base.js asset file.
  • var (str) – The obfuscated variable name that stores an object with all functions that descrambles the signature.

Example:

>>> get_transform_object(js, 'DE')
['AJ:function(a){a.reverse()}',
'VR:function(a,b){a.splice(0,b)}',
'kT:function(a,b){var c=a[0];a[0]=a[b%a.length];a[b]=c}']
pytube.cipher.get_transform_plan(js: str) → List[str][source]

Extract the “transform plan”.

The “transform plan” is the functions that the ciphered signature is cycled through to obtain the actual signature.

Parameters:js (str) – The contents of the base.js asset file.

Example:

[‘DE.AJ(a,15)’, ‘DE.VR(a,3)’, ‘DE.AJ(a,51)’, ‘DE.VR(a,3)’, ‘DE.kT(a,51)’, ‘DE.kT(a,8)’, ‘DE.VR(a,3)’, ‘DE.kT(a,21)’]

pytube.cipher.js_splice(arr: list, start: int, delete_count=None, *items)[source]

Implementation of javascript’s splice function.

Parameters:
  • arr (list) – Array to splice
  • start (int) – Index at which to start changing the array
  • delete_count (int) – Number of elements to delete from the array
  • *items –

    Items to add to the array

Reference: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice # noqa:E501

pytube.cipher.map_functions(js_func: str) → Callable[source]

For a given JavaScript transform function, return the Python equivalent.

Parameters:js_func (str) – The JavaScript version of the transform function.
pytube.cipher.reverse(arr: List[T], _: Optional[Any])[source]

Reverse elements in a list.

This function is equivalent to:

function(a, b) { a.reverse() }

This method takes an unused b variable as their transform functions universally sent two arguments.

Example:

>>> reverse([1, 2, 3, 4])
[4, 3, 2, 1]
pytube.cipher.splice(arr: List[T], b: int)[source]

Add/remove items to/from a list.

This function is equivalent to:

function(a, b) { a.splice(0, b) }

Example:

>>> splice([1, 2, 3, 4], 2)
[1, 2]
pytube.cipher.swap(arr: List[T], b: int)[source]

Swap positions at b modulus the list length.

This function is equivalent to:

function(a, b) { var c=a[0];a[0]=a[b%a.length];a[b]=c }

Example:

>>> swap([1, 2, 3, 4], 2)
[3, 2, 1, 4]
pytube.cipher.throttling_cipher_function(d: list, e: str)[source]

This ciphers d with e to generate a new list.

In the javascript, the operation is as follows: var h = [A-Za-z0-9-_], f = 96; // simplified from switch-case loop d.forEach(

function(l,m,n){
this.push(
n[m]=h[
(h.indexOf(l)-h.indexOf(this[m])+m-32+f–)%h.length

]

)

}, e.split(“”)

)

pytube.cipher.throttling_mod_func(d: list, e: int)[source]

Perform the modular function from the throttling array functions.

In the javascript, the modular operation is as follows: e = (e % d.length + d.length) % d.length

We simply translate this to python here.

pytube.cipher.throttling_nested_splice(d: list, e: int)[source]

Nested splice function in throttling js.

In the javascript, the operation is as follows: function(d,e){

e=(e%d.length+d.length)%d.length; d.splice(

0, 1, d.splice(

e, 1, d[0]

)[0]

)

}

While testing, all this seemed to do is swap element 0 and e, but the actual process is preserved in case there was an edge case that was not considered.

pytube.cipher.throttling_prepend(d: list, e: int)[source]

In the javascript, the operation is as follows: function(d,e){

e=(e%d.length+d.length)%d.length; d.splice(-e).reverse().forEach(

function(f){
d.unshift(f)

}

)

}

Effectively, this moves the last e elements of d to the beginning.

pytube.cipher.throttling_push(d: list, e: Any)[source]

Pushes an element onto a list.

pytube.cipher.throttling_reverse(arr: list)[source]

Reverses the input list.

Needs to do an in-place reversal so that the passed list gets changed. To accomplish this, we create a reversed copy, and then change each indvidual element.

pytube.cipher.throttling_swap(d: list, e: int)[source]

Swap positions of the 0’th and e’th elements in-place.

pytube.cipher.throttling_unshift(d: list, e: int)[source]

Rotates the elements of the list to the right.

In the javascript, the operation is as follows: for(e=(e%d.length+d.length)%d.length;e–;)d.unshift(d.pop())

Exceptions

Library specific exception definitions.

exception pytube.exceptions.AgeRestrictedError(video_id: str)[source]

Video is age restricted, and cannot be accessed without OAuth.

exception pytube.exceptions.ExtractError[source]

Data extraction based exception.

exception pytube.exceptions.HTMLParseError[source]

HTML could not be parsed

exception pytube.exceptions.LiveStreamError(video_id: str)[source]

Video is a live stream.

exception pytube.exceptions.MaxRetriesExceeded[source]

Maximum number of retries exceeded.

exception pytube.exceptions.MembersOnly(video_id: str)[source]

Video is members-only.

YouTube has special videos that are only viewable to users who have subscribed to a content creator. ref: https://support.google.com/youtube/answer/7544492?hl=en

exception pytube.exceptions.PytubeError[source]

Base pytube exception that all others inherit.

This is done to not pollute the built-in exceptions, which could result in unintended errors being unexpectedly and incorrectly handled within implementers code.

exception pytube.exceptions.RecordingUnavailable(video_id: str)[source]
exception pytube.exceptions.RegexMatchError(caller: str, pattern: Union[str, Pattern[AnyStr]])[source]

Regex pattern did not return any matches.

exception pytube.exceptions.VideoPrivate(video_id: str)[source]
exception pytube.exceptions.VideoRegionBlocked(video_id: str)[source]
exception pytube.exceptions.VideoUnavailable(video_id: str)[source]

Base video unavailable error.

Helpers

Various helper functions implemented by pytube.

class pytube.helpers.DeferredGeneratorList(generator)[source]

A wrapper class for deferring list generation.

Pytube has some continuation generators that create web calls, which means that any time a full list is requested, all of those web calls must be made at once, which could lead to slowdowns. This will allow individual elements to be queried, so that slowdowns only happen as necessary. For example, you can iterate over elements in the list without accessing them all simultaneously. This should allow for speed improvements for playlist and channel interactions.

generate_all()[source]

Generate all items.

pytube.helpers.cache(func: Callable[[...], GenericType]) → GenericType[source]

mypy compatible annotation wrapper for lru_cache

pytube.helpers.create_mock_html_json(vid_id) → Dict[str, Any][source]

Generate a json.gz file with sample html responses.

:param str vid_id
YouTube video id
:return dict data
Dict used to generate the json.gz file
pytube.helpers.deprecated(reason: str) → Callable[source]

This is a decorator which can be used to mark functions as deprecated. It will result in a warning being emitted when the function is used.

pytube.helpers.generate_all_html_json_mocks()[source]

Regenerate the video mock json files for all current test videos.

This should automatically output to the test/mocks directory.

Shortcut method to search a string for a given pattern.

Parameters:
  • pattern (str) – A regular expression pattern.
  • string (str) – A target string to search.
  • group (int) – Index of group to return.
Return type:

str or tuple
Returns:

Substring pattern matches.
pytube.helpers.safe_filename(s: str, max_length: int = 255) → str[source]

Sanitize a string making it safe to use as a filename.

This function was based off the limitations outlined here: https://en.wikipedia.org/wiki/Filename.

Parameters:
  • s (str) – A string to make safe for use as a file name.
  • max_length (int) – The maximum filename character length.
Return type:

str
Returns:

A sanitized string.
pytube.helpers.setup_logger(level: int = 40, log_filename: Optional[str] = None) → None[source]

Create a configured instance of logger.

Parameters:level (int) – Describe the severity level of the logs to handle.
pytube.helpers.target_directory(output_path: Optional[str] = None) → str[source]

Function for determining target directory of a download. Returns an absolute path (if relative one given) or the current path (if none given). Makes directory if it does not exist.

Returns:An absolute directory path as a string.
pytube.helpers.uniqueify(duped_list: List[T]) → List[T][source]

Remove duplicate items from a list, while maintaining list order.

:param List duped_list
List to remove duplicates from
:return List result
De-duplicated list

Request

Implements a simple wrapper around urlopen.

pytube.request.filesize[source]

Fetch size in bytes of file at given URL

Parameters:url (str) – The URL to get the size of
Returns:int: size in bytes of remote file
pytube.request.get(url, extra_headers=None, timeout=<object object>)[source]

Send an http GET request.

Parameters:
  • url (str) – The URL to perform the GET request for.
  • extra_headers (dict) – Extra headers to add to the request
Return type:

str
Returns:

UTF-8 encoded string of response
pytube.request.head(url)[source]

Fetch headers returned http GET request.

Parameters:url (str) – The URL to perform the GET request for.
Return type:dict
Returns:dictionary of lowercase headers
pytube.request.post(url, extra_headers=None, data=None, timeout=<object object>)[source]

Send an http POST request.

Parameters:
  • url (str) – The URL to perform the POST request for.
  • extra_headers (dict) – Extra headers to add to the request
  • data (dict) – The data to send on the POST request
Return type:

str
Returns:

UTF-8 encoded string of response
pytube.request.seq_filesize[source]

Fetch size in bytes of file at given URL from sequential requests

Parameters:url (str) – The URL to get the size of
Returns:int: size in bytes of remote file
pytube.request.seq_stream(url, timeout=<object object>, max_retries=0)[source]

Read the response in sequence. :param str url: The URL to perform the GET request for. :rtype: Iterable[bytes]

pytube.request.stream(url, timeout=<object object>, max_retries=0)[source]

Read the response in chunks. :param str url: The URL to perform the GET request for. :rtype: Iterable[bytes]