True or False

Part of the Python in a Game Window section of Coddy's Pygame journey. Lesson 14 of 32.

True and False are values of their own, called booleans. A variable can hold one, like a switch:

lamp_on = False

An if can test it directly: if lamp_on: runs when it holds True. not flips it, so lamp_on = not lamp_on switches the lamp.

A switch needs a key press, not a held key. get_pressed() is True on every frame the key is down, so it would flip the lamp 60 times a second. A press arrives once, as a KEYDOWN event, in the event loop at the top of the game loop:

for event in pygame.event.get():
    if event.type == pygame.QUIT:
        running = False
    if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
        lamp_on = not lamp_on

Section 2 explains events in full. For now: event.type says what happened and event.key which key.

Challenge

Medium

Make Space switch the lamp:

In the setup part, make lamp_on = False.
In the event loop, when a KEYDOWN event for K_SPACE arrives, set lamp_on = not lamp_on.
Draw the light at (320, 290), radius 30: (255, 220, 100) when lamp_on is True, otherwise (70, 70, 90).

Try it yourself

import pygame

pygame.init()
screen = pygame.display.set_mode((640, 480))
pygame.display.set_caption("Night Sky")
clock = pygame.time.Clock()

# Set things up here, before the game loop.

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Change things here, once a frame.

    screen.fill((20, 24, 48))
    # Draw here, after the fill.
    pygame.draw.rect(screen, (90, 90, 110), (310, 300, 20, 180))
    pygame.draw.circle(screen, (70, 70, 90), (320, 290), 30)

    pygame.display.flip()
    clock.tick(60)

pygame.quit()