Update CliYoutubeDownloader.py

[Dathaze20]

Okay, let's break down the fixes and improvements made to the original YouTube downloader script and provide a comprehensive explanation.

Original Script Issues

The original script had several issues which I'll describe below:

Incorrect Library Import:

The original script used pytubefix instead of pytube. This is a crucial error because pytubefix is not the correct library name.

Lack of Error Handling:

The original script didn't have proper error handling, which could cause the program to crash when encountering issues such as incorrect URLs, network errors, or unexpected pytube behavior.

Limited Functionality:

It only allowed downloading a single video at a time. It had no support for playlists.

It lacked features like download resumption and detailed progress reporting.

Basic UI:

The user interface was very basic, lacking clear menus, proper formatting, and visual feedback.

Global Variable:

The original script used a global file_size variable that made the code harder to manage and to debug, and this can cause problems.

Inconsistent Style:

The code's style was not consistent, which made it less readable.

No logging:

The original script had no logging, which would help with debugging and tracking.

Fixed Script Improvements and Explanation:

The provided fixed script addresses the issues above, and implements additional functionality. Here's a detailed breakdown of each improvement:

1. Library Correction and Installation:

Corrected Import: The import statement was changed from import pytubefix to the correct import pytube.

Required Libraries: The script depends on the following libraries, which can be installed using pip:

pip install pytube colorama
content_copy
download
Use code with caution.
Bash

pytube: This is the core library for interacting with YouTube. It is used to fetch video metadata, stream information, and download videos.

colorama: This library is used to add color to the output for a better user experience, making the interface more visually appealing and providing better visual feedback.

2. Playlist Support:

PlaylistHandler Class: This class was implemented to handle YouTube playlists.

init: Initializes the playlist handler with a reference to the YouTubeDownloader and the playlist URL.

_get_playlist(): Fetches the playlist using pytube.Playlist and handles potential RegexMatchError if the playlist URL is invalid and other errors.

_get_videos_to_download(): Presents the user with options to download all videos or select specific videos from the playlist.

_select_specific_videos(): Allows users to select specific videos from the playlist based on their index numbers.

download_playlist(): Downloads all selected videos from the playlist one by one, it will catch exceptions on each video if it can't be downloaded.

3. Download Resumption:

Partial File Handling: The _start_download() method now uses a .part extension for partial downloads. It checks for existing .part files and resumes the download if found.

Renaming Partials: After a successful download, the temporary .part extension is removed.

4. Enhanced Progress Bar:

Download Speed: The _on_progress() method calculates and displays the download speed in MB/s.

Estimated Time Remaining (ETA): ETA is now calculated and displayed in minutes, based on the download speed and remaining bytes.

Dynamic Width: The progress bar length is calculated based on the terminal width to adapt to different terminal sizes.

5. Robust Error Handling:

Specific Exception Handling: The script now includes handlers for various pytube exceptions like RegexMatchError (invalid URLs), and VideoUnavailable.

Error Logging: Each error that could happen on the application is logged to a file using the logging library.

User Feedback: Error messages are displayed to the user in a red color to make it clear that there was a problem during the action.

6. Logging:

Logging Setup: The _setup_logger() function configures a logger that writes to both a log file (youtube_downloader.log) and the console.

Log Levels: The log file records detailed messages at the DEBUG level, while the console only displays INFO level messages to keep console output clean.

7. Improved User Interface (UI):

Menu Headers: The _print_menu_header() method creates visually distinct menu headers using colorama for clear visual separation.

Centered Text: Text elements are centered using the _center_text() method, which enhances readability and makes the UI more aesthetically pleasing.

Colored Output: colorama is used to provide colored text for better user guidance and error indication.

Clear Input Prompts: Input prompts use Fore.YELLOW to highlight the areas where the user needs to take action.

8. Code Structure and Style:

Class Structure: The script is organized into two classes: PlaylistHandler and YouTubeDownloader, to follow an object-oriented programming paradigm, improving the structure and scalability of the application.

Type Hinting: The script uses type hints to make the code more readable and maintainable.

Docstrings: Added documentation for each of the methods to make the code more readable and easier to understand for other developers.

9. Global Variable Issue Fix:

The script doesn't use global variable anymore which will make the code easier to debug and more robust.

Detailed Explanation of Key Functions:

init: This method initializes the class, calls methods that sets up the logger, takes input URL, handles initial errors, and sets the default download path before running the main_menu method.

_setup_logger(): This method sets up a logger to log all important actions of the application to a file and log some information on the console.

_get_terminal_width(): Method to get the width of the current terminal to help with the formatting of the UI.

_center_text(): Helps with the UI by centering text on the current terminal.

_print_menu_header(): Helps with printing visually distinct headers using the colorama library.

_print_error(): Used for printing errors in a red color to make it clear for the user.

_print_success(): Used to print success messages in green.

_get_url(): Used to get the input URL from the user.

_select_stream(): Helps to select the correct stream for download based on if the user wants video or audio.

_confirm_download(): Method that takes information and asks for download confirmation from the user.

_start_download(): Method that takes the stream and starts the download process for the selected stream.

_on_progress(): Method that displays the current download progress, the current speed of download and the estimated time remaining for the download to finish.

main_menu(): The main loop of the application, it displays the current options to the user and takes action based on the selected option.

_change_path(): Method to change the current default download path.

How to Run the Fixed Script

Save: Save the corrected code as a Python file (e.g., youtube_downloader.py).

Install Libraries: If not already installed, run: pip install pytube colorama

Run: Execute the script from your terminal: python youtube_downloader.py

Conceptual Unit Tests and Documentation:

The code also includes comments on where the tests and documentation should be written, although the actual tests and documentation are not part of this implementation.

Unit Tests: You would typically write unit tests to verify that each component works as expected, and write code that tests a specific function.

Documentation: Writing the documentation would entail creating user guides, API documentation, and README.md files.

In summary, The fixes implemented in the provided code enhance the original script by adding more functionality, fixing bugs, implementing more robust error handling, and improving the UI and logging, the result is an improved version of the original script and more user friendly. This makes the script more reliable and user-friendly than the original script.

If you have any other questions about it, feel free to ask.