61、打印出杨辉三角形。
#python3.7
from sys import stdout
if __name__ == '__main__':
a = []
for i in range(10):
a.append([])
for j in range(10):
a[i].append(0)
for i in range(10):
a[i][0] = 1
a[i][i] = 1
for i in range(2,10):
for j in range(1,i):
a[i][j] = a[i - 1][j-1] + a[i - 1][j]
for i in range(10):
for j in range(i + 1):
stdout.write(str(a[i][j]))
stdout.write(' ')
print()
62、查找字符串。
#python3.7
sStr1 = 'language'
sStr2 = 'age'
print(sStr1.find(sStr2))
结果：
5
63、使用Tkinter画椭圆。
#python3.7
from tkinter import *
if __name__ == '__main__':
x = 360
y = 160
top = y - 30
bottom = y - 30
canvas = Canvas(width = 400, height = 600, bg = 'white')
for i in range(20):
canvas.create_oval(250 - top, 250 - bottom, 250 + top, 250 + bottom)
top -= 5
bottom += 5
canvas.pack()
mainloop()
64、利用ellipse 和 rectangle 画图。
#python3.7
from tkinter import *
if __name__ == '__main__':
canvas = Canvas(width = 400, height = 600, bg = 'white')
left = 20
right = 50
top = 50
num = 15
for i in range(num):
canvas.create_oval(250 - right, 250 - left, 250 + right, 250 + left)
canvas.create_oval(250 - 20, 250 - top, 250 + 20, 250 + top)
canvas.create_oval(20 - 2 * i, 20 - 2 * i, 10 * (i + 2), 10 * (i + 2))
right += 5
left += 5
top += 10
canvas.pack()
mainloop()
65、一个最优美的图案。
#python3.7
from tkinter import *
import math
class PTS:
def __init__(self):
self.x = 0
self.y = 0
points = []
def LineToDemo():
screenx = 400
screeny = 400
canvas = Canvas(width = screenx, height = screeny, bg = 'white')
AspectRatio = 0.85
MAXPTS = 15
h = screeny
w = screenx
xcenter = w / 2
ycenter = h / 2
radius = (h - 30) / (AspectRatio * 2) - 20
step = 360 / MAXPTS
angle = 0.0
for i in range(MAXPTS):
rads = angle * math.pi / 180.0
p = PTS()
p.x = xcenter + int(math.cos(rads) * radius)
p.y = ycenter - int(math.sin(rads) * radius * AspectRatio)
angle += step
points.append(p)
canvas.create_oval(xcenter - radius, ycenter - radius,
xcenter + radius, ycenter + radius)
for i in range(MAXPTS):
for j in range(i, MAXPTS):
canvas.create_line(points[i].x, points[i].y, points[j].x,points[j].y)
canvas.pack()
mainloop()
if __name__ == '__main__':
LineToDemo()
66、输入3个数a,b,c，按大小顺序输出。
#python3.7
if __name__ == '__main__':
n1 = int(input('n1 = \n'))
n2 = int(input('n2 = \n'))
n3 = int(input('n3 = \n'))
def swap(p1, p2):
return p2, p1
if n1 > n2: n1, n2 = swap(n1, n2)
if n1 > n2: n1, n3 = swap(n1, n3)
if n2 > n3: n2, n3 = swap(n2, n3)
print(n1, n2, n3)
参考资料：
Python 100例
