Name a Value

Part of the Python in a Game Window section of Coddy's Pygame journey. Lesson 5 of 32.

A variable is a name for a value. A single = stores the value on its right under the name on its left:

moon_x = 500
moon_y = 110

pygame.draw.circle(screen, (240, 230, 160), (moon_x, moon_y), 50)

Wherever Python meets moon_x, it uses the value stored there, 500. Change the number in one place and every line that uses the name follows.

= does not mean "is equal" as in maths. It means "store": moon_x = 160 puts 160 in moon_x, replacing what was there.

A name is made of letters, digits and underscores, and starts with a letter. Capitals count: Moon_x is another name. Pick names that say what the value is.

Make variables in the setup part, before the game loop. The loop then reads them on every frame.

Challenge

Easy

Put the moon's position in variables:

In the setup part, make moon_x = 160 and moon_y = 120.
Draw the moon at (moon_x, moon_y), radius 50, in its usual colour.

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.circle(screen, (240, 230, 160), (500, 110), 50)

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

pygame.quit()