遇到的测试笔试题-打印菱形

键盘就收数字n ,输出2*n+1行的菱形

如：n=2

打印为：  *

           ***

             *

代码为：

def printUpTriangle(x,y):
    print(" "*(y+1-x)+"*"*(2*x-1)+" "*(y+1-x))

def printDownTriangle(x,y):
    print(" "*(x-y-1)+"*"*(2*((2*y+1)-x)+1)+" "*(x-y-1))


n = int(raw_input("please input num: "))

for i in range(1,(2*n+2)):
    if(i<=n):
        printUpTriangle(i,n)
    elif(i==(n+1)):
        print("*"*(2*n+1))
    elif(i>n+1):
        printDownTriangle(i,n)