Alleger les mouvement et déplacements

Bonjour,
je voudrais que mon personnage ne part et ne s'arrête pas brutalement quand une touche de mon ordinateur est appuyé. voici un exemple: si on est immobile et qu'on se met à courir, on ne vas pas tout de suite aller à sa vitesse maximale, pareil pour s'arrêter, on met quelques secondes pour être complètement immobile.
j'ai donc essayé et cela marche seulement pour le départ. voici mon code.
main.py:

import pygame, sys
from game import Game

pygame.init()

screen = pygame.display.set_mode((1199, 800))
icon = pygame.image.load('icon_and_background/icon.png')
pygame.display.set_caption('the game')
pygame.display.set_icon(icon)
game = Game

running = True

while running:
    pygame.display.flip() 
    screen.blit(game.background_2, (0,0))
    screen.blit(game.background_1, (0, 740))
    screen.blit(game.player.skin, game.player.rect)

    if game.pressed.get(pygame.K_q) and game.player.can_move_left:
        game.player.can_move_right = False
        game.player.move_left()
        game.player.speed_add()

    if game.pressed.get(pygame.K_q) == False and game.player.can_move_right == False:
        if game.player.speed > 1.9:
            for i in range(20):
                game.player.speed -= 0.1
        if game.player.speed < 1.9:
            game.player.speed = 0.1
        game.player.can_move_right = True

    if game.pressed.get(pygame.K_d) and game.player.can_move_right:
        game.player.can_move_left = False
        game.player.move_right()
        game.player.speed_add()

    if game.pressed.get(pygame.K_d) == False and game.player.can_move_left == False:
        game.player.speed = 0.1
        game.player.can_move_left = True


    '''elif game.pressed == False:
        game.player.speed_remove()
        if game.pressed.get(pygame.K_q) == False and game.player.can_move_right == False:
            game.player.can_move_right = True

        if game.pressed.get(pygame.K_d) == False and game.player.can_move_left == False:
            game.player.can_move_left = True
'''
    print(game.player.speed)
    for event in pygame.event.get():

        if event.type == pygame.QUIT: 
            running = False 

        if event.type == pygame.KEYDOWN:
            game.pressed[event.key] = True
        elif event.type == pygame.KEYUP:
            game.pressed[event.key] = False
pygame.quit() 
sys.exit() 

game.py

import pygame
from player import Player

class Game():

    player = Player()
    pressed = {}
    background_1 = pygame.image.load('icon_and_background/bg1.jpg')
    background_2 = pygame.image.load('icon_and_background/bg2.jpg)

player.py

import pygame

class Player(pygame.sprite.Sprite):

    def __init__(self):
        super().__init__()
        self.speed = 0.1
        self.skin = pygame.image.load('player/player_right.png')
        self.rect = self.skin.get_rect()
        self.rect.x = 100.0
        self.posx = self.rect.x
        self.rect.y = 670.0
        self.can_move_left = True
        self.can_move_right = True

    def move_left(self):

        self.posx -= self.speed
        self.rect.x = self.posx
        self.skin = pygame.image.load('player/player_left.png')

    def move_right(self):

        self.posx += self.speed
        self.rect.x = self.posx
        self.skin = pygame.image.load('player/player_right.png')

    def speed_add(self):
        if self.speed <= 2.0:
            self.speed += 0.01

voila j'espère que ce soit réalisable et merci de me répondre le plus rapidement possible.