Store the original (not rotated) image in the class and store the position of the car in a pygame.math.Vector2 object:
def __init__(self, surf, x, y, speed, angle):
# [...]
self.surf = surf.convert()
self.surf.set_colorkey(black)
self.pos = pygame.math.Vector2(x, y)
# [...]
Chang the position of the car dependent on the direction. The direction vector is set by self.speed (in y direction) and has to be rotated by self.angle. Note that (.rotate()) rotates in counter clockwise direction. The y-axis points downwards, so when w is pressed, then the vector has to be subtracted and when s is pressed, then the vector has to be add to self.pos:
def update(self):
# [...]
dirvec = pygame.math.Vector2(0, self.speed).rotate(self.angle)
if keys[pygame.K_w]:
self.pos = self.pos - dirvec
elif keys[pygame.K_s]:
self.pos = self.pos + dirvec
Rotate the image and update the rectangle. See also How do I rotate an image around its center using Pygame?:
def update(self):
# [...]
self.image = pygame.transform.rotate(self.surf, -self.angle)
self.rect = self.image.get_rect(center = (round(self.pos.x), round(self.pos.y)))
Full code of the class Car:
class Car(pygame.sprite.Sprite):
def __init__(self, surf, x, y, speed, angle):
super().__init__()
self.surf = surf
self.surf.set_colorkey(black)
self.pos = pygame.math.Vector2(x, y)
self.angle = angle
self.speed = speed
self.image = pygame.transform.rotate(self.surf, self.angle)
self.rect = self.image.get_rect(center=(x, y))
def update(self):
keys = pygame.key.get_pressed()
if keys[pygame.K_a]:
self.angle -= 10
elif keys[pygame.K_d]:
self.angle += 10
dirvec = pygame.math.Vector2(0, self.speed).rotate(self.angle)
if keys[pygame.K_w]:
self.pos = self.pos - dirvec
elif keys[pygame.K_s]:
self.pos = self.pos + dirvec
if self.pos.x > 800:
self.pos.x = 0
elif self.pos.x < 0:
self.pos.x = 800
elif self.pos.y > 600:
self.pos.y = 0
elif self.pos.y < 0:
self.pos.y = 600
self.image = pygame.transform.rotate(self.surf, -self.angle)
self.rect = self.image.get_rect(center = (round(self.pos.x), round(self.pos.y)))
See also How to turn the sprite in pygame while moving with the keys
repl.it/@Rabbid76/PyGame-CarMovement