杨辉三角

def pascal_triangle(n):
    if n == 1:
        return [ 1 ]
    elif n == 2:
        return [1, 1]
    else:
        list = []
        list.append(1)
        for i in range(1, n-1):
            list.append(pascal_triangle(n-1)[i-1] + pascal_triangle(n-1)[i])

        list.append(1)
        return list

print(pascal_triangle(9))
for i in range(9):
    print(pascal_triangle(i))