Python 练习实例56
Python 100例题目：画图，学用circle画圆形。
程序分析：无。
程序源代码：
实例(Python 2.0+)
#!/usr/bin/python
# -*- coding: UTF-8 -*-
if __name__ == '__main__':
from Tkinter import *
canvas = Canvas(width=800, height=600, bg='yellow')
canvas.pack(expand=YES, fill=BOTH)
k = 1
j = 1
for i in range(0,26):
canvas.create_oval(310 - k,250 - k,310 + k,250 + k, width=1)
k += j
j += 0.3
mainloop()
以上实例输出结果为：
使用 turtle 模块 ：
#usr/bin/env python #coding:utf-8 if __name__ == '__main__': import turtle turtle.title("画圆") turtle.setup(800,600,0,0) pen=turtle.Turtle() pen.color("yellow") pen.width(5) pen.shape("turtle") pen.speed(1) pen.circle(100)画出10个半径依次增加定长的同心圆:
#!/usr/bin/python # -*- coding: UTF-8 -*- import numpy as np import matplotlib.pyplot as plt x = y = np.arange(-11, 11, 0.1) x, y = np.meshgrid(x,y) #圆心为（0，0），半径为1-10 for i in range(1,11): plt.contour(x, y, x**2 + y**2, [i**2]) #如果删除下句，得出的图形为椭圆 plt.axis('scaled') plt.show()import math as m import matplotlib.pyplot as plt x=[] y=[] for a in range(1,11): for b in range(0,360): x.append(a*(m.cos(m.pi*(b/180)))) y.append(a*(m.sin(m.pi*(b/180)))) plt.scatter(x,y,s=30) plt.axis([-11,11,-11,11]) #避免因比例而压缩为椭圆 plt.axis('equal') plt.show()