pafy

0.5.5 verified Fri May 01 auth: no python maintenance

pafy is a Python library to retrieve YouTube content and metadata, such as video titles, descriptions, thumbnails, and download URLs. Current version is 0.5.5, with no set release cadence; the project appears to be in maintenance mode with infrequent updates.

pip install pafy

Common errors

error AttributeError: module 'pafy' has no attribute 'new' ↓

cause Importing pafy incorrectly (e.g., 'import pafy.new' instead of 'from pafy import new').

fix

Use 'import pafy' then 'pafy.new(...)' or 'from pafy import new'.

error pafy.util.GdataError: No data returned ↓

cause YouTube API key missing or invalid, or videos are age-restricted/private.

fix

Ensure video is public and not restricted. Set API key via pafy.set_api_key('YOUR_KEY').

error IOError: [Errno 2] No such file or directory: 'youtube-dl' ↓

cause youtube-dl executable not installed or not in PATH.

fix

Install youtube-dl: pip install youtube-dl and ensure it's in PATH.

Warnings

deprecated pafy uses youtube-dl as its backend, which is no longer actively maintained and may break with YouTube changes. Consider using yt-dlp as a replacement. ↓

fix Switch to yt-dlp with pafy: pip install yt-dlp and set pafy.backend = 'youtube-dl' (though yt-dlp is not natively supported). Better to use yt-dlp directly.

gotcha pafy.new blocks on network calls; calling it in a GUI or async context may freeze the application. ↓

fix Run pafy.new in a thread or use an async-compatible library instead.

breaking As of pafy 0.5.5, the default backend relies on youtube-dl, which may frequently break due to YouTube API changes. Ensure youtube-dl is up to date. ↓

fix Update youtube-dl frequently: pip install --upgrade youtube-dl. Or switch to yt-dlp based forks.

Install

pip install pafy youtube-dl

Imports

pafy
```
import pafy
```
new
wrong
```
import pafy.new
```
correct
```
from pafy import new
```
Do not import pafy and try to call pafy.new; use 'from pafy import new' or 'pafy.new' after import pafy

Quickstart

Fetch metadata from a YouTube video using pafy and print title, views, duration, and best stream URL.

import pafy

url = 'https://www.youtube.com/watch?v=dQw4w9WgXcQ'
video = pafy.new(url)
print(video.title)
print(video.viewcount)
print(video.duration)
stream = video.getbest()
print(stream.url)