API¶
YouTube Object¶
-
class
pytube.
YouTube
(url: str, defer_prefetch_init: bool = False, on_progress_callback: Optional[pytube.monostate.OnProgress] = None, on_complete_callback: Optional[pytube.monostate.OnComplete] = None, proxies: Dict[str, str] = None)[source]¶ Core developer interface for pytube.
Get the video author. :rtype: str
Interface to query caption tracks.
Return type: CaptionQuery
.
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descramble
() → None[source]¶ Descramble the stream data and build Stream instances.
The initialization process takes advantage of Python’s “call-by-reference evaluation,” which allows dictionary transforms to be applied in-place, instead of holding references to mutations at each interstitial step.
Return type: None
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initialize_stream_objects
(fmt: str) → None[source]¶ Convert manifest data to instances of
Stream
.Take the unscrambled stream data and uses it to initialize instances of
Stream
for each media stream.Parameters: fmt (str) – Key in stream manifest ( ytplayer_config
) containing progressive download or adaptive streams (e.g.:url_encoded_fmt_stream_map
oradaptive_fmts
).Return type: None
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prefetch
() → None[source]¶ Eagerly download all necessary data.
Eagerly executes all necessary network requests so all other operations don’t does need to make calls outside of the interpreter which blocks for long periods of time.
Return type: None
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register_on_complete_callback
(func: pytube.monostate.OnComplete)[source]¶ Register a download complete callback function post initialization.
Parameters: func (callable) – A callback function that takes stream
andfile_path
.Return type: None
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register_on_progress_callback
(func: pytube.monostate.OnProgress)[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 - A callback function that takes
-
streams
¶ Interface to query both adaptive (DASH) and progressive streams.
Return type: StreamQuery
.
Stream Object¶
-
class
pytube.
Stream
(stream: Dict[KT, VT], player_config_args: 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.
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download
(output_path: Optional[str] = None, filename: Optional[str] = None, filename_prefix: Optional[str] = None, skip_existing: bool = True) → 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
Returns: Path to the saved video
Return type:
-
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
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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
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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:
-
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.
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StreamQuery Object¶
-
class
pytube.query.
StreamQuery
(fmt_streams)[source]¶ Interface for querying the available media streams.
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all
() → List[pytube.streams.Stream][source]¶ Get all the results represented by this query as a list.
Return type: list
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asc
() → pytube.query.StreamQuery[source]¶ Sort streams in ascending order.
Return type: StreamQuery
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count
(value: Optional[str] = None) → int[source]¶ Get the count of items in the list.
Return type: int
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desc
() → pytube.query.StreamQuery[source]¶ Sort streams in descending order.
Return type: StreamQuery
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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 NoneReturns: 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 NoneReturns: 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 NoneReturns: 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 NoneReturns: 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 NoneReturns: 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 NoneReturns: 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 NoneReturns: 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.
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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
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Extract¶
This module contains all non-cipher related data extraction logic.
-
pytube.extract.
apply_descrambler
(stream_data: Dict[KT, VT], key: str) → 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 adict
and unquoting the value.Parameters: 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'}]}
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pytube.extract.
apply_signature
(config_args: Dict[KT, VT], fmt: str, js: str) → None[source]¶ Apply the decrypted signature to the stream manifest.
Parameters:
-
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.
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.
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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.
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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.
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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: Return type: 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.
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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
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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:
-
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 callDE.AJ(a,15)
returned by the transform plan, “DE” would be the var.Parameters: 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}']
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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)’]
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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.
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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]
Exceptions¶
Library specific exception definitions.
-
exception
pytube.exceptions.
PytubeError
[source]¶ Base pytube exception that all others inherent.
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.
RegexMatchError
(caller: str, pattern: Union[str, Pattern[AnyStr]])[source]¶ Regex pattern did not return any matches.
Video is unavailable.
Mixins¶
Helpers¶
Various helper functions implemented by pytube.
-
pytube.helpers.
cache
(func: Callable[[...], GenericType]) → GenericType[source]¶ mypy compatible annotation wrapper for lru_cache
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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.
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pytube.helpers.
regex_search
(pattern: str, string: str, group: int) → str[source]¶ Shortcut method to search a string for a given pattern.
Parameters: Return type: Returns: Substring pattern matches.
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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: Return type: Returns: A sanitized string.
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pytube.helpers.
setup_logger
(level: int = 40)[source]¶ Create a configured instance of logger.
Parameters: level (int) – Describe the severity level of the logs to handle.
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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.
Request¶
Implements a simple wrapper around urlopen.
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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
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pytube.request.
get
(url) → str[source]¶ Send an http GET request.
Parameters: url (str) – The URL to perform the GET request for. Return type: str Returns: UTF-8 encoded string of response
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pytube.request.
head
(url: str) → Dict[KT, VT][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
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pytube.request.
stream
(url: str, chunk_size: int = 4096, range_size: int = 9437184) → Iterable[bytes][source]¶ Read the response in chunks. :param str url: The URL to perform the GET request for. :param int chunk_size: The size in bytes of each chunk. Defaults to 4KB :param int range_size: The size in bytes of each range request. Defaults to 9MB :rtype: Iterable[bytes]