python - 用python turtle 画花

我正在学习使用python编程（指think python 2），并被某个程序所震撼。问题陈述：Python program to draw a symmetric flower after seeking the size of and number of petals from user。

我想出的代码在下面，除了我无法在数学上正确获得每个花瓣之间的角度（在接近结束状态的代码中，该部分表示bob.lt(360/petal)）。有人可以帮忙吗？

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）

最佳答案

只需像这样修改代码（在draw_petals中添加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)