How can I make pygame.key.get_pressed() more responsive?

Question

Here is the beginnings of my code for a snake game. There is an annoying delay between pressing an arrow key and the snake's actual turning.

It's hard to turn accurately and grab the 'apple'.

I'd like for this to be more responsive. How can I tweak my code to make the turning more responsive?

import random
import pygame
pygame.init()

#----------------------------
# CONSTANTS
#----------------------------

window_width = 800
window_height = 800
segment_size = 24

win = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption('Snake Game')

#----------------------------
# CLASSES
#----------------------------
class Segment:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.width = segment_size
        self.height = segment_size
        self.vel = segment_size
        self.dir = 'right'

    def move(self):
        if self.dir == 'right':
            self.x += self.vel
        elif self.dir == 'left':
            self.x -= self.vel
        elif self.dir == 'up':
            self.y -= self.vel
        else:
            self.y += self.vel

class Apple:
    def __init__(self):
        self.x = (random.randint(0, window_width//segment_size)) * segment_size
        self.y = (random.randint(0, window_height//segment_size)) * segment_size
        self.width = segment_size
        self.height = segment_size
        self.vel = segment_size

#----------------------------
# FUNCTIONS
#----------------------------

def draw_grid(win):
    for x in range (0, window_width, segment_size):
        pygame.draw.line(win, (75, 75, 75), (x, 0), (x, window_height), 1)
    for y in range (0, window_height, segment_size):
        pygame.draw.line(win, (75, 75, 75), (0, y), (window_width, y), 1)

#----------------------------
# REDRAW WINDOW
#----------------------------

def redraw_window(win):
    win.fill((0, 0, 0)) # fill screen with black
    draw_grid(win) # draw grid
    pygame.draw.rect(win, (255, 255, 255), (s.x, s.y, s.width, s.height)) # draw snake
    pygame.draw.rect(win, (255, 0, 0), (a.x, a.y, a.width, a.height)) # draw apple
    s.move() # move snake
    pygame.display.update()

#----------------------------
# MAIN GAME LOOP
#----------------------------
clock = pygame.time.Clock()

segments = []
s = Segment(48, 48)
a = Apple()

running = True
while running:    

    clock.tick(30)

    # listen for window closure
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # listen for key presses
    keys = pygame.key.get_pressed()
    for key in keys:
        if keys[pygame.K_LEFT]:
            s.dir = 'left'
        if keys[pygame.K_RIGHT]:
            s.dir = 'right'
        if keys[pygame.K_UP]:
            s.dir = 'up'
        if keys[pygame.K_DOWN]:
            s.dir = 'down'

    redraw_window(win)

pygame.quit()

Is there anything else you would do here to optimize the code at this point. Thank you!

Answer 1

Increase your clock rate from 30 to 60 or 90 as it will update your game more often:

clock.tick(90)

instead of

clock.tick(30)

just make sure to decrease the speed at which your snake is moving because increasing clock rate will mean more iterations of the game loop per second and therefore the snake's movement will be increased more frequently

Answer 2

This:

# listen for key presses
keys = pygame.key.get_pressed()
for key in keys:
    if keys[pygame.K_LEFT]:
        s.dir = 'left'
    if keys[pygame.K_RIGHT]:
        s.dir = 'right'
    if keys[pygame.K_UP]:
        s.dir = 'up'
    if keys[pygame.K_DOWN]:
        s.dir = 'down'

is unnecessary.

You aren't using the key variable so there is no point of having that for loop. Do this instead:

# listen for key presses
keys = pygame.key.get_pressed()

if keys[pygame.K_LEFT]:
    s.dir = 'left'
if keys[pygame.K_RIGHT]:
    s.dir = 'right'
if keys[pygame.K_UP]:
    s.dir = 'up'
if keys[pygame.K_DOWN]:
    s.dir = 'down'