Python: Youtube video downloader

#!/usr/bin/env python3

# Version 12

# Prevent creation of the __pycache__ directory.
# SOURCE: https://github.com/pytest-dev/pytest/issues/200
import sys
sys.dont_write_bytecode = True

# -----

import ctypes
import uuid
def known_folder(idstr):
    # Convert the GUID string (e.g. '{374DE...}') into a UUID object,
    # then get its little-endian 16-byte representation as required by Windows.
    fid = uuid.UUID(idstr).bytes_le

    # Create a real C array of 16 unsigned bytes initialized with the GUID bytes.
    # This produces a stable block of memory that SHGetKnownFolderPath() can read.
    guid = (ctypes.c_byte * 16)(*fid)

    # Prepare a wchar* (wide char pointer) to receive the resulting folder path.
    # SHGetKnownFolderPath will allocate and fill this pointer.
    out = ctypes.c_wchar_p()

    # Call the Windows API:
    #   HRESULT SHGetKnownFolderPath(
    #       REFKNOWNFOLDERID rfid,  // pointer to our 16-byte GUID
    #       DWORD dwFlags,          // we pass 0 (default behavior)
    #       HANDLE hToken,          // None = current user
    #       PWSTR *ppszPath         // receives allocated wide-string path
    #   )
    ctypes.windll.shell32.SHGetKnownFolderPath(
        guid,             # pointer to 16-byte GUID array
        0,                # flags = 0
        None,             # user token = current user
        ctypes.byref(out) # address of out pointer to receive the path
    )

    # Return the actual string value (Python automatically converts wchar*).
    return out.value

# Common Known Folders GUIDs (user profile related only).
KnownFolders = {
    'Desktop':               '{B4BFCC3A-DB2C-424C-B029-7FE99A87C641}',
    'Documents':             '{FDD39AD0-238F-46AF-ADB4-6C85480369C7}',
    'Downloads':             '{374DE290-123F-4565-9164-39C4925E467B}',
    'Music':                 '{4BD8D571-6D19-48D3-BE97-422220080E43}',
    'Pictures':              '{33E28130-4E1E-4676-835A-98395C3BC3BB}',
    'Videos':                '{18989B1D-99B5-455B-841C-AB7C74E4DDFC}',

    'Favorites':             '{1777F761-68AD-4D8A-87BD-30B759FA33DD}',
    'Links':                 '{BFB9D5E0-C6A9-404C-B2B2-AE6DB6AF4968}',

    'SavedGames':            '{4C5C32FF-BB9D-43B0-B5B4-2D72E54EAAA4}',
    'SavedSearches':         '{7D1D3A04-DEBB-4115-95CF-2F29DA2920DA}',
    'Contacts':              '{56784854-C6CB-462B-8169-88E350ACB882}',
    'AppDataLocal':          '{F1B32785-6FBA-4FCF-9D55-7B8E7F157091}',
    'AppDataLocalLow':       '{A520A1A4-1780-4FF6-BD18-167343C5AF16}',
    'AppDataRoaming':        '{3EB685DB-65F9-4CF6-A03A-E3EF65729F3D}',

    'DesktopDirectory':      '{B4BFCC3A-DB2C-424C-B029-7FE99A87C641}', # same as Desktop
    'Profile':               '{5E6C858F-0E22-4760-9AFE-EA3317B67173}', # C:\Users\<User>
    'Public':                '{DFDF76A2-C82A-4D63-906A-5644AC457385}',

    'OneDrive':              '{A52BBA46-E9E1-435f-B3D9-28DAA648C0F6}',
    'OneDriveDocuments':     '{24D89E24-2F19-4534-9DDE-6A6671FBB8FE}',
    'OneDrivePictures':      '{339719B5-8C47-4894-94C2-D8F77ADD44A6}',
    'OneDriveMusic':         '{0077D3A4-6F62-46A1-8F79-6BCB9B93D15B}',
}

# -----

# Winget adds yt-dlp.exe to PATH so don't need to hard code it here.
YT_DLP_PATH = r'yt-dlp'

DOWNLOAD_DIRECTORY = known_folder(KnownFolders['Downloads'])

# -----

import ctypes
import os
import subprocess
import sys

def is_admin():
    try:
        if sys.platform == 'win32':
            return ctypes.windll.shell32.IsUserAnAdmin()
        else:
            return os.geteuid() == 0
    except:
        return False

def check_permissions():
    if is_admin():
        return
    print('Requesting administrative privileges . . .')
    try:
        if sys.platform == 'win32':
            params = ' '.join([f'"{arg}"' for arg in sys.argv])
            result = ctypes.windll.shell32.ShellExecuteW(None, 'runas', sys.executable, params, None, 1)
            if result <= 32: # SOURCE: https://learn.microsoft.com/en-us/windows/win32/api/shellapi/nf-shellapi-shellexecutew If the function succeeds, it returns a value greater than 32.
                sys.exit(1)
        else:
            try:
                script = os.path.abspath(sys.argv[0])
                args = [script] + sys.argv[1:]
                subprocess.run(['sudo', sys.executable] + args)
            except KeyboardInterrupt:
                pass
    except Exception as e:
        print(f'An error occurred: {e}')
    sys.exit()

def update_yt_dlp():
    # Update yt-dlp and wait for it to finish.
    print('Updating yt-dlp . . .')
    try:
        subprocess.run([YT_DLP_PATH, '--update'], check=True)
    except subprocess.CalledProcessError as e:
        print('ERROR: Failed to update yt-dlp.', e)
        check_permissions() # Restart script and try again with administrator privileges.

        # If script is already running as administrator.
        wait_for_any_keypress()
        sys.exit(1)

def get_video_url():
    url = None
    while True:
        try:
            url = input('Youtube URL: ')
            if not str_is_none_or_whitespace(url):
               break
            clear()
        except ValueError as e:
            print(e)
    return url

def str_is_none_or_whitespace(text):
    return not text or text.isspace()

import os
def clear():
    os.system('cls' if os.name in ('nt', 'dos') else 'clear')

import subprocess
def main():
    update_yt_dlp()
    print()

    print('Download Directory:', DOWNLOAD_DIRECTORY)
    print()

    url = get_video_url()
    print()

    subprocess.run([YT_DLP_PATH, '--list-formats', url])

    cmd = [
            YT_DLP_PATH,
             '-f', 'bestvideo+bestaudio', # yt-dlp chooses what it thinks is the "best" combination (sometimes not the absolute largest resolution).
            #'-f', 'bv*+ba*', # explicitly forces maximum resolution video and best audio, no matter what yt-dlp's ranking says.

            #'-f', 'bestvideo[vcodec=vp9]+bestaudio', # yt-dlp assumes AV1 is "better" because it's newer and more efficient, but if your goal is maximum resolution + maximum bitrate, you need to override its preference. (VP9) → larger file, higher bitrate, potentially better quality if you want maximum fidelity.
            #'--merge-output-format', 'mp4', # re-encoding may cause quality loss.

            '--output', '%(title)s-%(id)s.%(ext)s',
            '--verbose',
        ]

    #  cookies_path = os.path.join(os.getcwd(), 'cookies.txt')
    #  if os.path.exists(cookies_path):
    #      cmd += ['--cookies', cookies_path]
    #      print(f'Loading cookies: {cookies_path}')
    #  else:
    #      print('WARNING: cookies.txt not found in the current directory. Proceeding without cookies.')

    # SOURCE: https://github.com/yt-dlp/yt-dlp/wiki/FAQ
    # Firefox/Librewolf: User agent from about:support
    # Brave: User agent from brave://version
    # Chrome: User agent from chrome://version
    cmd += ['--user-agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:153.0) Gecko/20100101 Firefox/153.0']

    # SOURCE: https://github.com/yt-dlp/yt-dlp/issues/14050
    if os.name in ('nt', 'dos'):
        cmd += ['--cookies-from-browser', 'firefox:%APPDATA%/librewolf']
    else:
        # TODO: Untested
        cmd += ['--cookies-from-browser', 'firefox:${HOME}/.librewolf/']
        #cmd += ['--cookies-from-browser', 'firefox:./.librewolf/']

    cmd.append(url)
    try:
        subprocess.run(cmd, cwd=DOWNLOAD_DIRECTORY, check=True)
    except subprocess.CalledProcessError as e:
        print('ERROR: Failed to download video from url:', url)
        wait_for_any_keypress()
        sys.exit(1)

    print('Download complete . . .')
    print()

    wait_for_any_keypress()

# ----- Press any key to continue -----

def wait_for_any_keypress():
    import sys
    if sys.platform == 'win32':
        import os
        os.system('pause')
    elif sys.platform.startswith('linux') or sys.platform == 'darwin':
        print('Press any key to continue . . .')
        import termios
        import tty
        stdin_file_desc = sys.stdin.fileno()
        old_stdin_tty_attr = termios.tcgetattr(stdin_file_desc)
        try:
            tty.setraw(stdin_file_desc)
            sys.stdin.read(1)
        finally:
            termios.tcsetattr(stdin_file_desc, termios.TCSADRAIN, old_stdin_tty_attr)

if __name__ == '__main__':
    main()