Python: Password Generator

#!/usr/bin/env python3

# Version 6

# POSTED ONLINE: https://pastebin.com/g10jVftx

# Windows: $ pip install pyperclip asciimatics
# Linux:   $ sudo pacman -S python-pyperclip
#          $ sudo pacman -S wl-clipboard    <-- Pyperclip has issues with KDE + Wayland. Installing this seems to get it to work.
#          $ yay -S python-asciimatics
# NOTE: For Linux you also need to install a copy/paste mechanism if you don't have one. KDE has /bin/klipper installed by default, otherwise try [$ sudo pacman -S xclip] or [$ sudo pacman -S xsel].
#       If you get error "Cannot find '.setClipboardContents' in object /klipper at org.kde.klipper",
#       its because klipper isn't running on startup. Try Start > klipper and see if the problem goes away.
#       To display klipper in taskbar right click the ^ > Configure System Tray... > Entries > Clipboard: [Show when relevant].

import pyperclip
from asciimatics.screen import Screen
from asciimatics.event import KeyboardEvent

# -----

def draw_menu(screen, menuItems, selectedIndex, title=''):
    # Clear screen.
    clear(screen)

    # Draw title.
    if title:
        writeline(screen, title)

    # Draw menu items.
    for i in range(len(menuItems)):
        writeline(screen, f' {"●" if i == selectedIndex else "○"} {menuItems[i]}', Screen.COLOUR_GREEN if i == selectedIndex else Screen.COLOUR_CYAN)
    writeline(screen)

    # Draw usage information.
    writeline(screen, ' Make → Space', Screen.COLOUR_YELLOW)
    writeline(screen, ' Copy → Enter', Screen.COLOUR_YELLOW)
    writeline(screen, ' Rise → Up', Screen.COLOUR_YELLOW)
    writeline(screen, ' Fall → Down', Screen.COLOUR_YELLOW)
    writeline(screen, ' Smol → Left', Screen.COLOUR_YELLOW)
    writeline(screen, ' Swol → Right', Screen.COLOUR_YELLOW)
    writeline(screen, ' Quit → Escape', Screen.COLOUR_YELLOW)

    # Draw screen.
    screen.refresh()

# -----

def clear(screen):
    global current_line
    current_line = 0
    screen.clear()

# -----

current_line = 0
def writeline(screen, text='', color=Screen.COLOUR_WHITE):
    global current_line
    lines = text.split('\n')
    for i, line in enumerate(lines):
        screen.print_at(line, 0, current_line, color)
        current_line += 1

# -----

from datetime import datetime
def generate_timestamped_passwords(password_length, count=5):
    dt = datetime.now()
    SHORT_TIME_STAMP = dt.strftime('%y%m%d')
    SHORT_TIME_STAMP_LENGTH = len(SHORT_TIME_STAMP)
    reducedLength = password_length - SHORT_TIME_STAMP_LENGTH
    passwords = [SHORT_TIME_STAMP + generate_password(reducedLength) for i in range(count)]

    LARGE_TIME_STAMP = dt.strftime('%Y-%m-%d %H:%M:%S')
    timestamp =  f' Created: {LARGE_TIME_STAMP}\n'
    timestamp += f' Length: {password_length}\n'
    return passwords, timestamp

# -----

import string
import secrets
def generate_password(password_length):
    # Comment out or add usable characters here.
    PASSWORD_CHARACTERS = [
        string.ascii_lowercase,
        string.ascii_uppercase,
        string.digits,
        string.punctuation,
    ]

    characters = "".join(PASSWORD_CHARACTERS)

    # SOURCE: https://docs.python.org/3/library/secrets.html
    password = ''.join(secrets.choice(characters) for i in range(password_length))
    return password

# -----

def wait_for_any_keypress(screen):
    writeline(screen, ' Press any key to continue . . . ')
    screen.refresh()

    # Wait for user keyboard input indefinitely.
    while True:
        screen.wait_for_input(5) # Sleep for this many seconds while waiting for input. This prevents 100% CPU usage from the loop.
        ev = screen.get_event()
        if isinstance(ev, KeyboardEvent):
            break

# -----

MIN_PASSWORD_LENGTH = 8

def main(screen):
    password_length = 23
    menuItems, timestamp = generate_timestamped_passwords(password_length)
    selectedIndex = 0
    draw_menu(screen, menuItems, selectedIndex, timestamp) # Initial drawing.

    while True:
        # Get keyboard input.
        screen.wait_for_input(5) # Sleep for this many seconds while waiting for input. This prevents 100% CPU usage from the loop.
        ev = screen.get_event()
        if not isinstance(ev, KeyboardEvent):
            continue

        # If Escape key is pressed.
        elif ev.key_code == -1:
            break

        # If Space key is pressed.
        elif ev.key_code == ord(' '):
            menuItems, timestamp = generate_timestamped_passwords(password_length)

        # If Up key is pressed.
        elif ev.key_code == Screen.KEY_UP:
            # Loop around backwards.
            selectedIndex = (selectedIndex - 1 + len(menuItems)) % len(menuItems)

        # If Down key is pressed.
        elif ev.key_code == Screen.KEY_DOWN:
            # Loop around forwards.
            selectedIndex = (selectedIndex + 1) % len(menuItems)

        # If Left key is pressed.
        elif ev.key_code == Screen.KEY_LEFT:
            # Reduce length of passwords.
            password_length = max(MIN_PASSWORD_LENGTH, password_length - 1)
            menuItems, timestamp = generate_timestamped_passwords(password_length)

        # If Right key is pressed.
        elif ev.key_code == Screen.KEY_RIGHT:
            # Increase length of passwords.
            password_length = password_length + 1
            menuItems, timestamp = generate_timestamped_passwords(password_length)

        # If Enter key is pressed.
        # NOTE: On Windows the enter key appears to be \r, and on Linux its \n.
        elif ev.key_code == ord('\r') or ev.key_code == ord('\n'):
            pyperclip.copy(menuItems[selectedIndex])
            writeline(screen, f"\n Copied {menuItems[selectedIndex]} to clipboard.\n")
            wait_for_any_keypress(screen)

        # Else an unexpected key is pressed.
        #  else:
        #      try:
        #          writeline(screen, "\n The pressed key '{}' {} is not associated with a menu function.\n".format(chr(ev.key_code), ev.key_code))
        #      except ValueError:
        #          writeline(screen, "\n The pressed key {} is not associated with a menu function.\n".format(ev.key_code))
        #      wait_for_any_keypress(screen)

        draw_menu(screen, menuItems, selectedIndex, timestamp)

if __name__ == '__main__':
    Screen.wrapper(main)