pytube: [BUG] RegexMatchError: get_throttling_function_name: could not find match for multiple

I have confirmed that I am on the latest version of pytube by installing from the source. I did this by running !pip install git+https://github.com/pytube/pytube.

Describe the bug

Since today I’m encountering a RegexMatchError when trying to download a YouTube video using pytube. The error message suggests that the function get_throttling_function_name could not find a match for multiple. It was working fine until yesterday and I didn’t do anything to the code.

To Reproduce

The video URL that is causing the error is: https://www.youtube.com/watch?v=oMHLkcc9I9c&ab_channel=NENA

Here is the code where the problem is occurring:

from pytube import YouTube

yt = YouTube("https://www.youtube.com/watch?v=oMHLkcc9I9c&ab_channel=NENA")
yt.streams

Expected behavior

I expected the video to be downloaded without any errors.

Output

Here is the full traceback for the exception:

---------------------------------------------------------------------------
RegexMatchError                           Traceback (most recent call last)
[~\AppData\Roaming\Python\Python38\site-packages\pytube\__main__.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/__main__.py) in fmt_streams(self)
    180         try:
--> 181             extract.apply_signature(stream_manifest, self.vid_info, self.js)
    182         except exceptions.ExtractError:

[~\AppData\Roaming\Python\Python38\site-packages\pytube\extract.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/extract.py) in apply_signature(stream_manifest, vid_info, js)
    408     """
--> 409     cipher = Cipher(js=js)
    410 

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in __init__(self, js)
     42 
---> 43         self.throttling_plan = get_throttling_plan(js)
     44         self.throttling_array = get_throttling_function_array(js)

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_plan(js)
    404         The contents of the base.js asset file.
--> 405     :returns:
    406         The full function code for computing the throttlign parameter.

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_function_code(js)
    310     :returns:
--> 311         The name of the function used to compute the throttling parameter.
    312     """

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_function_name(js)
    295                     array = array.group(1).strip("[]").split(",")
--> 296                     array = [x.strip() for x in array]
    297                     return array[int(idx)]

RegexMatchError: get_throttling_function_name: could not find match for multiple

During handling of the above exception, another exception occurred:

RegexMatchError                           Traceback (most recent call last)
 in 
      1 #yt = YouTube("https://www.youtube.com/watch?v=8JIncRMkr00&pp=ygU7SSdtIEluIExvdmUgRHViIFBpc3RvbHMgZmVhdC4gTGluZHkgTGF5dG9uICYgUm9kbmV5IFAgbXVzaWM%3D")
      2 yt = YouTube("https://www.youtube.com/watch?v=oMHLkcc9I9c&ab_channel=NENA")
----> 3 yt.streams

[~\AppData\Roaming\Python\Python38\site-packages\pytube\__main__.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/__main__.py) in streams(self)
    294         """
    295         self.check_availability()
--> 296         return StreamQuery(self.fmt_streams)
    297 
    298     @property

[~\AppData\Roaming\Python\Python38\site-packages\pytube\__main__.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/__main__.py) in fmt_streams(self)
    186             pytube.__js__ = None
    187             pytube.__js_url__ = None
--> 188             extract.apply_signature(stream_manifest, self.vid_info, self.js)
    189 
    190         # build instances of :class:`Stream `

[~\AppData\Roaming\Python\Python38\site-packages\pytube\extract.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/extract.py) in apply_signature(stream_manifest, vid_info, js)
    407 
    408     """
--> 409     cipher = Cipher(js=js)
    410 
    411     for i, stream in enumerate(stream_manifest):

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in __init__(self, js)
     41         ]
     42 
---> 43         self.throttling_plan = get_throttling_plan(js)
     44         self.throttling_array = get_throttling_function_array(js)
     45 

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_plan(js)
    403     :param str js:
    404         The contents of the base.js asset file.
--> 405     :returns:
    406         The full function code for computing the throttlign parameter.
    407     """

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_function_code(js)
    309     :rtype: str
    310     :returns:
--> 311         The name of the function used to compute the throttling parameter.
    312     """
    313     # Begin by extracting the correct function name

[~\AppData\Roaming\Python\Python38\site-packages\pytube\cipher.py](https://file+.vscode-resource.vscode-cdn.net/c%3A/Users/Maurice/Code/Music_Recommendation/~/AppData/Roaming/Python/Python38/site-packages/pytube/cipher.py) in get_throttling_function_name(js)
    294                 if array:
    295                     array = array.group(1).strip("[]").split(",")
--> 296                     array = [x.strip() for x in array]
    297                     return array[int(idx)]
    298 

RegexMatchError: get_throttling_function_name: could not find match for multiple

I already tried removing the semicolon as suggested in 1707 but it didn’t work for me.

System information Please provide the following information:

Python 3.8.1
15.0.0
pip install pytube (but I did “python -m pip install git+https://github.com/pytube/pytube” as suggested)
I use VS Code

About this issue

Original URL
State: open
Created a year ago
Reactions: 8
Comments: 23

Most upvoted comments

I did many tests and I can confirm it works, but the download speed is far lower than usual.

Here are some the download speed I got:

downloaded in      30.37 seconds     at speed         316.60 kB/s
downloaded in      20.47 seconds     at speed          46.13 kB/s
downloaded in      16.87 seconds     at speed          54.87 kB/s
downloaded in      23.06 seconds     at speed         437.26 kB/s
downloaded in      20.93 seconds     at speed       1,288.54 kB/s
downloaded in      32.14 seconds     at speed         538.38 kB/s
downloaded in      27.80 seconds     at speed          28.67 kB/s
downloaded in      28.10 seconds     at speed         378.43 kB/s
downloaded in      31.73 seconds     at speed         675.31 kB/s
downloaded in      32.36 seconds     at speed          26.40 kB/s
downloaded in      33.19 seconds     at speed       1,649.87 kB/s
downloaded in      13.64 seconds     at speed          69.36 kB/s
downloaded in      33.52 seconds     at speed          26.18 kB/s
downloaded in      14.62 seconds     at speed         258.11 kB/s
downloaded in      42.43 seconds     at speed       2,123.43 kB/s
downloaded in      41.57 seconds     at speed         123.60 kB/s
downloaded in      45.57 seconds     at speed           9.91 kB/s
downloaded in      42.59 seconds     at speed         107.25 kB/s
downloaded in      44.01 seconds     at speed       1,285.29 kB/s
downloaded in      12.58 seconds     at speed         371.68 kB/s
downloaded in      19.63 seconds     at speed         119.63 kB/s
downloaded in      18.96 seconds     at speed         162.03 kB/s
downloaded in      38.84 seconds     at speed          13.18 kB/s
downloaded in      62.54 seconds     at speed          12.88 kB/s
downloaded in      66.01 seconds     at speed         808.10 kB/s
downloaded in       9.19 seconds     at speed         538.32 kB/s
downloaded in       8.29 seconds     at speed       1,018.81 kB/s
downloaded in      27.40 seconds     at speed       4,351.08 kB/s
downloaded in      15.88 seconds     at speed         171.19 kB/s
downloaded in       8.13 seconds     at speed         168.79 kB/s
downloaded in      18.02 seconds     at speed       1,022.75 kB/s
downloaded in      11.60 seconds     at speed          73.62 kB/s
downloaded in      11.02 seconds     at speed          54.26 kB/s
downloaded in      11.63 seconds     at speed         357.40 kB/s

NannoSilver on Aug 10, 2023

from cipher.py i deleted another one question mark and now, my program runs smoothly, so in cipher.py i have regex like this:

r'a\.[a-zA-Z]\s*&&\s*\([a-z]\s*=\s*a\.get\("n"\)\)\s*&&.*\|\|\s*([a-z]+)',
        r'\([a-z]\s*=\s*([a-zA-Z0-9$]+)(\[\d+\])\([a-z]\)'

Mc-Kappa on Aug 11, 2023

.*? This matches the smallest possible part of the text when the other parts of the expression are matched .* This matches the biggest possible part of the text when the other parts of the expression are matched When using the first option, an incorrect element of the code could be determined, due to which the decryption of the key could be incorrect. And then YouTube cuts the speed. When replacing the expression with the second one, the required function began to be determined, the decryption began to proceed successfully, and YouTube stopped cutting speed.

YuriiMaiboroda on Oct 29, 2023

I have a question: why does it seem like “cypher.py” is where the most errors occur?

Because this code do parsing and processing the script coming from YouTube. If YouTube changes something, the processing algorithm may become out of date and require modification.

YuriiMaiboroda on Oct 29, 2023

I have a question: why does it seem like “cypher.py” is where the most errors occur?

LaniakeaArmstrong on Oct 29, 2023

I agree with all, I faced the issue today and replaced the above code, it works but significantly impacts download speeds.

akawari on Aug 10, 2023

Not to speak out of turn for this repo, but adding comments saying “me too” add a lot of noise to the discussion. Feel free to just thumbs-up the original post to let the maintainers know you’re watching the thread

It is not bad at all. When people say “same problem here” or something like that, will count-up at the list of “issues” and attract attention of others for which is the thread of the issues affecting everybody. Helping to concentrate the discussions and reducing the number of threads.

comments

NannoSilver on Aug 10, 2023

That worked for me too, but seems to have some abnormal delay to start the download:

In cipher.py locate:
        r'a\.[a-zA-Z]\s*&&\s*$[a-z]\s*=\s*a\.get\("n"$\)\s*&&.*?\|\|\s*([a-z]+)',
        r'$[a-z]\s*=\s*([a-zA-Z0-9$]+)(\[\d+\])?\([a-z]$',
And replace by:
        r'a\.[a-zA-Z]\s*&&\s*$[a-z]\s*=\s*a\.get\("n"$\)\s*&&.*?\|\|\s*([a-z]+)',
        r'$[a-z]\s*=\s*([a-zA-Z0-9$]+)(\[\d+\])\([a-z]$',
The only change is the removal of a ?

It works but the data download speed is awful

oszlsm on Aug 10, 2023

Not to speak out of turn for this repo, but adding comments saying “me too” add a lot of noise to the discussion. Feel free to just thumbs-up the original post to let the maintainers know you’re watching the thread

qupterra on Aug 10, 2023

https://github.com/pytube/pytube/issues/1707#issuecomment-1672149709 This work for me

YuriiMaiboroda on Aug 9, 2023