键盘事件的图案如何保存

Question

我使用了键盘事件，如何当我按向上键的时候，产生的线条能长时间停留在画面上
现在他只是闪一下线条，我想让他能一直出现

import pygame
import sys


def Morse_code(x):
    '''
    function:返回对应的摩斯码
    '''
    dic = {'A': '._', 'B': '_...', 'C': '_._.', 'D': '_..', 'E': '.', 'F': '.._.',
           'G': '__.', 'H': '....', 'I': '..', 'J': '.___', 'K': '_._', 'L': '._..',
           'M': '__', 'N': '_.', 'O': '___', 'P': '.__.', 'Q': '__._', 'R': '._.',
           'S': '...', 'T': '_', 'U': '.._', 'V': '..._', 'W': '.__', 'X': '_.._',
           'Y': '_.__', 'Z': '__..',
           '1': '.____', '2': '..___', '3': '...__', '4': '...._', '5': '.....',
           '6': '_....', '7': '__...', '8': '___..', '9': '____.', '0': '_____',
           ' ': ' '}
    if x in dic:
        return dic[x]


def Turn_Morse_code(s):
    '''
    function:将字符串转为摩斯密码串
    '''
    s = s.upper()  # 将小写字母转换为大写字母
    num = len(s)
    Morsecode = ''
    i = 0
    for i in range(num):
        Morsecode += str(Morse_code(s[i]))
    return Morsecode
s:str = "ILOVEYOU"
Morse = Turn_Morse_code(s)


pygame.init()
pygame.mixer.init()
ck = pygame.display.set_mode((800,500))   #  游戏窗口
pygame.display.set_caption("发报机")    #  给窗口取个名
clock = pygame.time.Clock()                         #  游戏刷新速度
start_ck = pygame.Surface(ck.get_size())    #   充当开始界面的画布
start_ck2 = pygame.Surface(ck.get_size())  #  充当第一关的画布界面暂时占位
start_ck3 = pygame.Surface(ck.get_size())
start_ck = start_ck.convert()
start_ck2 = start_ck2.convert()
start_ck.fill((255,255,255))  # 白色画布1（开始界面用的）
start_ck2.fill((255,255,255))
start_ck3.fill((255,255,255))
# 加载各个素材 并且赋予变量名
track = pygame.mixer.music.load("./sound/sound.mp3")
i1 = pygame.image.load("./s1.png")
i1.convert()
i11 = pygame.image.load("./s2.png")
i11.convert()

i2 = pygame.image.load("./n2.png")
i2.convert()
i21 = pygame.image.load("./n1.png")
i21.convert()


bg = pygame.image.load('./bi.jpg')
bg.convert()
f = pygame.font.Font('./WETPET.TTF',50)

pygame.mixer.music.play()
#  以下为选择开始界面鼠标检测结构。
n1 = True
while n1:
    clock.tick(30)
    buttons = pygame.mouse.get_pressed()
    x1, y1 = pygame.mouse.get_pos()
    if x1 >= 227 and x1 <= 555 and y1 >= 141 and y1 <=207:
        start_ck.blit(i11, (200, 120))
        if buttons[0]:
            n1 = False

    elif x1 >= 227 and x1 <= 555 and y1 >= 271 and y1 <=337:
        start_ck.blit(i21, (200, 230))
        if buttons[0]:
            pygame.quit()
            exit()

    else:
        start_ck.blit(i1, (200, 120))
        start_ck.blit(i2, (200, 230))


    ck.blit(start_ck,(0,0))
    pygame.display.update()


    # 下面是监听退出动作

    # 监听事件
    for event in pygame.event.get():

        # 判断事件类型是否是退出事件
        if event.type == pygame.QUIT:
            print("游戏退出...")

            # quit 卸载所有的模块
            pygame.quit()

            # exit() 直接终止当前正在执行的程序
            sys.exit()
ck.blit(start_ck2,(0,0))


deviation = 0
pos = 800
deviation1 = 0
pos1 = 0

n2 = True
while n2:
    clock.tick(30)
    ck.blit(start_ck2, (0, 0))
    start_ck2.blit(bg, (0, 0))

    # render(text, antialias, color, background=None) -> Surface
    text = f.render("I LOVE YOU", True, (255, 50, 50), (255, 255, 255))
    # 获得显示对象的 rect区域大小
    textRect = text.get_rect()
    # 设置显示对象居中
    textRect.center = (400, 100)
    start_ck2.blit(text, textRect)

    pygame.display.update()

    for i in Morse:
        if i == '.':
            pygame.draw.line(start_ck2, (125, 20, 220), (pos - deviation, 200), (pos + 10 - deviation, 200), 70)
            pos += 20
        if i == '_':
            pygame.draw.line(start_ck2, (220, 150, 20), (pos - deviation, 200), (pos + 30 - deviation, 200), 70)
            pos += 40
    pos = 800
    deviation += 1
    pygame.display.update()

    for event in pygame.event.get():
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                pygame.draw.line(start_ck2, (125, 20, 220), (pos1 + deviation1, 400), (pos1 + 10 + deviation1, 400), 70)
                pos1 += 20


            if event.key == pygame.K_DOWN:
                pygame.draw.line(start_ck2, (220, 150, 20), (pos1 + deviation1, 400), (pos1 + 30 + deviation1, 400), 70)
                pos1 += 40
        pos = 800
        deviation += 1
    pygame.display.update()

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()

Answer 1

如果要移动就deviation+=1，不然就deviation+=0