打印出杨辉三角形（要求打印出10行）

def yh_triangle(num):
    triangle = []
    for i in range(num):
        triangle.append([])
        triangle[i].append(1)
        for j in range(1, i+1):
            if j == i:
                triangle[i].append(1)
                break
            else:
                triangle[i].append(triangle[i-1][j-1] + triangle[i-1][j])
        print(' '.join(str(x) for x in triangle[i]))


if __name__ == '__main__':
    yh_triangle(10)

#!/usr/bin/python
# -*- coding: UTF-8 -*-
 
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]
    from sys import stdout
    for i in range(10):
        for j in range(i + 1):
            stdout.write(str(a[i][j]))
            stdout.write(' ')
        print

以上实例输出结果为：

1 
1 1 
1 2 1 
1 3 3 1 
1 4 6 4 1 
1 5 10 10 5 1 
1 6 15 20 15 6 1 
1 7 21 35 35 21 7 1 
1 8 28 56 70 56 28 8 1 
1 9 36 84 126 126 84 36 9 1