绘制星星与蟒蛇中的龟

Question

我需要写一个函数，根据人们想要多少星星的问题绘制随机星星。 a =颜色，b =长度和c，d是起始坐标。我不确定我要去哪里错误的任何提示，提示或帮助，将不胜感激。

import turtle 
from random import* 
def star(a,b,c,d): 
    x=5 
    y=0 
    turtle.color(a) 
    turtle.begin_fill() 
    turtle.penup() 
    turtle.goto(c,d) 
    turtle.pendown() 
    while x>0: 
     turtle.forward(b) 
     turtle.right(144) 
     turtle.forward(b) 
     x-=1 
    turtle.end_fill() 

star('red',100,0,0) 

def random_color(): 
    randvar=randrange(0,5) 
    if randvar==0: 
     return ('red') 
    elif randvar==1: 
     return ('blue') 
    elif randvar==2: 
     return ('green') 
    elif randvar==3: 
     return ('yellow') 
    else: 
     return ('black') 

def length(): 
    randvar=randrange(5,71) 

def x(): 
    randvar=randrange(-280,281) 

def y(): 
    randvar=randrange(-200,201) 

def night_sky(): 
    z=int(input('How many stars do you want?')) 
    a=random_color 
    b=length 
    c=x 
    d=y 
    while z>0: 
     star(a,b,c,d) 
     z-=1 

Answer 1

要调用函数，把括号函数名后：

a=random_color() 
    b=length() 
    c=x() 
    d=y() 

---

确保你在脚本的末尾调用night_sky()。目前，只有

star('red',100,0,0) 

被调用。这就是为什么你只看到一颗星星。

---

功能length，x和y需要使用return。否则，默认返回None。

def length(): 
    return randrange(5,71) 

def x(): 
    return randrange(-280,281) 

def y(): 
    return randrange(-200,201) 

---

您需要将定义a，b，c，并d到while -loop的陈述，以免同一颗恒星被绘制z倍。虽然我们是在它的while -loop可以更简单地写成for -loop：

for i in range(z): 
     a=random_color() 
     b=length() 
     c=x() 
     d=y() 
     star(a,b,c,d) 

---

你的代码，如果你使用更具描述性的变量名会变得更加自我说明：

def star(color, side_length, x, y): 
    print(color, side_length, x, y) 
    turtle.color(color) 
    turtle.begin_fill() 
    turtle.penup() 
    turtle.goto(x, y) 
    turtle.pendown() 
    for i in range(5): 
     turtle.forward(side_length) 
     turtle.right(144) 
     turtle.forward(side_length) 
    turtle.end_fill() 

---

所以这些变化，代码变为：

import turtle 
import random 

def star(color, side_length, x, y): 
    print(color, side_length, x, y) 
    turtle.color(color) 
    turtle.begin_fill() 
    turtle.penup() 
    turtle.goto(x, y) 
    turtle.pendown() 
    for i in range(5): 
     turtle.forward(side_length) 
     turtle.right(144) 
     turtle.forward(side_length) 
    turtle.end_fill() 


def random_color(): 
    randvar = randrange(0, 5) 
    if randvar == 0: 
     return ('red') 
    elif randvar == 1: 
     return ('blue') 
    elif randvar == 2: 
     return ('green') 
    elif randvar == 3: 
     return ('yellow') 
    else: 
     return ('black') 


def length(): 
    return random.randrange(5, 71) 


def xcoord(): 
    return random.randrange(-280, 281) 


def ycoord(): 
    return random.randrange(-200, 201) 


def night_sky(): 
    z = int(input('How many stars do you want?')) 
    for i in range(z): 
     color = random_color() 
     side_length = length() 
     x = xcoord() 
     y = ycoord() 
     star(color, side_length, x, y) 

night_sky()