Use tkinter to create the GUI and use pytube to download video clips.
The 「package：tkinter(Tk interface)」 is the standard Python interface to the Tcl/Tk GUI toolkit.
The tkinter package implements the following interfaces：
- Input interface for Youtube video URL
- Download folder selection interface
- The interface for obtaining and displaying the list of video resolutions
- Video quality selection interface
- Video download interface
The 「package：pytube」 is a lightweight, Pythonic, dependency-free, library(and command-line utility) for downloading YouTube Videos.
APP usage steps are as follows：
- Enter the YouTube video URL
- Select the video storage folder
- Get the list of video resolutions
- Select the desired video quality
- Download the video