绘图与蟒蛇龟的花

Question

我正在学习使用python进行编程（引用思考python 2）并且对程序感到震惊。问题陈述：Python program to draw a symmetric flower after seeking the size of and number of petals from user。

我提出的代码如下所示，除了我无法在数学上正确地获得每个花瓣之间的角度（结束时代码的部分状态bob.lt(360/petal)）。有人可以在这帮忙吗？

import math
radius=int(input("What is the radius of the flower? "))
petals=int(input("How many petals do you want? "))
#radius=100
#petals=4


def draw_arc(b,r):  #bob the turtle,corner-to-corner length (radius) of petal (assume 60 degree central angle of sector for simplicity)
    c=2*math.pi*r #Circumference of circle
    ca=c/(360/60)  #Circumference of arc (assume 60 degree central angle of sector as above)
    n=int(ca/3)+1  #number of segments
    l=ca/n  #length of segment
    for i in range(n):
        b.fd(l)
        b.lt(360/(n*6))

def draw_petal(b,r):
    draw_arc(b,r)
    b.lt(180-60)
    draw_arc(b,r)

import turtle
bob=turtle.Turtle()

#draw_petal(bob,radius)

for i in range(petals):
    draw_petal(bob,radius)
    bob.lt(360/petals)

turtle.mainloop()

正确（对称） 不正确（不对称）

Answer 1

只需像这样修改您的代码（在draw_petals添加b.rt(360/petals-30并将bob.lt(360/petals)更正为360/4）：

import math
radius=int(input("What is the radius of the flower? "))
petals=int(input("How many petals do you want? "))
#radius=100
#petals=4


def draw_arc(b,r):  #bob the turtle,corner-to-corner length (radius) of petal (assume 60 degree central angle of sector for simplicity)
    c=2*math.pi*r #Circumference of circle
    ca=c/(360/60)  #Circumference of arc (assume 60 degree central angle of sector as above)
    n=int(ca/3)+1  #number of segments
    l=ca/n  #length of segment
    for i in range(n):
        b.fd(l)
        b.lt(360/(n*6))


def draw_petal(b,r):
    draw_arc(b,r)
    b.lt(180-60)
    draw_arc(b,r)
    b.rt(360/petals-30)  # this will take care of the correct angle b/w petals


import turtle
bob=turtle.Turtle()
#draw_petal(bob,radius)

for i in range(petals):
    draw_petal(bob,radius)
    bob.lt(360/4)

Answer 2

我认为这个问题比你做的更简单。

第一个问题是画一个花瓣改变了龟的标题，你正在尝试做数学将它设置回它开始的地方。在这里我们可以在绘制花瓣之前记录标题并在之后恢复它，没有数学。

第二个问题是当你使用turtle.circle()的扩展名参数执行此操作时，你可以实现自己的弧代码，这会产生相同的结果但速度更快：

from turtle import Turtle, Screen

def draw_petal(turtle, radius):
    heading = turtle.heading()
    turtle.circle(radius, 60)
    turtle.left(120)
    turtle.circle(radius, 60)
    turtle.setheading(heading)

my_radius = int(input("What is the radius of the flower? "))
my_petals = int(input("How many petals do you want? "))

bob = Turtle()

for _ in range(my_petals):
    draw_petal(bob, my_radius)
    bob.left(360 / my_petals)

bob.hideturtle()

screen = Screen()
screen.exitonclick()

<强> USAGE

> python3 test.py
What is the radius of the flower? 100
How many petals do you want? 10

<强>输出