.. _quickstart:

Quickstart
==========

This guide will walk you through the basic usage of pytube.

Let's get started with some examples.

Downloading a Video
-------------------

Downloading a video from YouTube with pytube is incredibly easy.

Begin by importing the YouTube class::

    >>> from pytube import YouTube

Now, let's try to download a video. For this example, let's take something
like the YouTube Rewind video for 2019::

    >>> yt = YouTube('http://youtube.com/watch?v=2lAe1cqCOXo')

Now, we have a :class:`YouTube <pytube.YouTube>` object called ``yt``.

The pytube API makes all information intuitive to access. For example, this is
how you would get the video's title::

    >>> yt.title
    YouTube Rewind 2019: For the Record | #YouTubeRewind

And this would be how you would get the thumbnail url::

    >>> yt.thumbnail_url
    'https://i.ytimg.com/vi/2lAe1cqCOXo/maxresdefault.jpg'

Neat, right? For advanced use cases, you can provide some additional arguments
when you create a YouTube object::

    >>> yt = YouTube(
            'http://youtube.com/watch?v=2lAe1cqCOXo',
            on_progress_callback=progress_func,
            on_complete_callback=complete_func,
            proxies=my_proxies
        )

When instantiating a YouTube object, these named arguments can be passed in to
improve functionality. 

The on_progress_callback function will run whenever a chunk is downloaded from
a video, and is called with three arguments: the stream, the data chunk, and
the bytes remaining in the video. This could be used, for example, to display a
progress bar.

The on_complete_callback function will run after a video has been fully
downloaded, and is called with two arguments: the stream and the file path.
This could be used, for example, to perform post-download processing on a video
like trimming the length of it.

Once you have a YouTube object set up, you're ready to start looking at
different media streams for the video, which is discussed in the next section.