p005_sum_of_square

代码1：

def sum_of_square(n):
    result=0
    while n>0:
        result+=n**2
        n-=1
    return result

print("Sum of square (3) is: " ,sum_of_square(3))
print("Sum of square (3.14) is: " ,sum_of_square(3.14))
print("Sum of square (9) is: " ,sum_of_square(9))

代码2：

def sum_of_square(n):
    result=0
   # while n>0:
    #    result+=n**2
    #    n-=1'''
    for i in range(0,n+1):
        result+=n**2
    return result

print("Sum of square (3) is: " ,sum_of_square(3))
print("Sum of square (4) is: " ,sum_of_square(4))
print("Sum of square (9) is: " ,sum_of_square(9))

效果1：

Sum of square (3) is:  14
Sum of square (3.14) is:  15.7584
Sum of square (9) is:  285

效果2：

Sum of square (3) is:  36
Sum of square (4) is:  80
Sum of square (9) is:  810

　　这是因为：n=3,循环0,1,2,3共四次，每次result=3**2，所以是3**2*9=36；4**2*5=80;9**2*10=810

总结：

1. n-=1意思为：n=n-1.n-=n,意思为：n=n-n；
2. while里面n可以使float类型，range(0,n+1)，这个n必须是整数。