Python YouTube Video Downloader

Question

I'm looking for some feedback on my first 'real' Python program. Started with Python a few days ago and wanted to get right into it and make something hands on.

Currently the program lets you download audio and video for a YouTube video using Pytube. It allows you specify the location to save the download, whether to download Audio or Video and what resolution to download videos at.

#global variables
yt = None
res = None
stream = None
file_path = None
av_swtich = None
#see if the user wants to download audio or video
def av_select():
 global av_switch
 print('Would you like to download Video or Audio:')
 while True:
 av_switch = input('Please enter \'1\' for Video and \'2\' for Audio\n')
 if av_switch not in ('1', '2'):
 print('Pleae make a valid selection')
 continue
 else:
 break
#Download Audio Stream
def audio_download():
 global yt
 global file_path
 print('The Video has the following audio streams')
 print(*yt.streams.filter(only_audio=True), sep='\n')
 while True:
 itag = input('Please Enter the Itag of the stream you want to download:\n')
 try:
 yt.streams.get_by_itag(str(itag)).download(output_path=str(file_path), filename_prefix='Audio-')
 print('The audio stream has been downloaded')
 return True
 except:
 print('You have entered an invalid Itag')
 continue
 
#Define Download location 
def download_location():
 global file_path
 while True:
 file_path = input('Please enter the Folder to save the Video in:\n')
 x = os.path.exists(path = str(file_path))
 if x == True:
 break
 else:
 print('The specified Folder does not exit')
 continue
#Select the video that the user wants to use
def video_select():
 global yt
 while True:
 video = input('Please enter the video URL:\n')
 try:
 yt = YouTube(video)
 print('The title of the video you selected is: ' + yt.title)
 return False
 except:
 print('The URL is not Valid\n')
 continue
#Select resoultion and display possible stings
def resoultion_select():
 global res
 global res_list
 while True:
 res = input('Please enter a Resoultion:\n')
 try:
 res_list = yt.streams.filter(resolution= str(res))
 return False
 except:
 print('You have entered an invalid resoultion')
 continue
#Select the stream to download based on the itag
def download_stream():
 global file_path
 global yt
 global res_list
 print('The Video has the following streams')
 print(*res_list, sep='\n')
 while True:
 itag = input('Please Enter the Itag of the stream you want to download:\n')
 try:
 yt.streams.get_by_itag(str(itag)).download(str(file_path))
 print('The video has been downloaded')
 return True
 except:
 print('You have entered an invalid Itag')
 continue
def Main():
 global av_switch
 print('Welcome to the Youtube Video Downloader\n')
 download_location()
 video_select()
 av_select()
 if av_switch == '1':
 resoultion_select()
 download_stream()
 else:
 audio_download()
 
Main()

• hjpotter92: "using Pytube" nowhere in the code I see pytube being imported. please provide a complete program.
• Ruperto: it is seen that on function download_stream(), the line "yt.streams.get_by_itag(str(itag)).download(str(file_path))" downloads the stream into "file_path" . 'hope it helps
• Mast: Please do not update the code in your question to incorporate feedback from answers, doing so goes against the Question + Answer style of Code Review. This is not a forum where you should keep the most updated version in your question. Please see what you may and may not do after receiving answers .

Answer 1

Global variables

• one major suggestion - don't (over)use global variables, it's generally not a good practice and it will make more difficult to test the code. For example if you'd like to add a functionality for downloading multiple items at the same time you'll have a hard time with it.

So instead of this:

def av_select():
 global av_switch # this function is setting value for this variable
def Main():
 global av_switch # this function is reading this variable
 av_select()

do this:

def av_select():
 while True:
 av_switch = input('Please enter \'1\' for Video and \'2\' for Audio\n')
 if av_switch not in ('1', '2'):
 print('Please make a valid selection')
 continue
 return av_switch # add return statement with the value
def Main():
 av_switch = av_select() # use the value returned from function
 if av_switch == '1':

same applies to other global variables.

Python coding guidelines

• follow PEP 8 guidelines, in this case the name of the function Main is violating it - function names should be lowercase.

• recommended way how to do code comments is to use docstrings. Instead of this:

#Define Download location 
def download_location():

do this:

def download_location():
 """define download location"""

this way the comment can be accessed as download_location.__doc__ and a lot of tools (eg. for generating documentation) can work with it.

Code flow

• the following one is probably a matter of taste, but it feels like you're overusing while True: loops in places where you can rely on other variables you are "waiting" for. For example av_select() - I'd use the aw_switch variable as a condition of the loop this way:

def av_select():
 av_switch = None
 while av_switch not in ('1', '2'):
 av_switch = input('Please enter \'1\' for Video and \'2\' for Audio\n')
 # outside the while loop, av_switch finally matches '1' or '2'
 return av_switch

Answer 2

Please add these imports at first and 2nd line of the code:

import os
from pytube import YouTube

Also, the full path of the destination folder needs to be entered when code asks 'Please enter the Folder to save the Video in'.