python-代码复用（函数）

##多个返回值
def sumDiff(x,y):
    return x+y,x-y

n1,n2 = eval(input(‘输入两个数：‘))
s,d = sumDiff(n1,n2)
print(‘和为{}，差为{}‘.format(s,d))

##计算三角形周长
import math

def square(x):
    return x*x
#计算两点之间的距离
def distance(x1,x2,y1,y2):
    dist = math.sqrt(square(x1-x2) + square(y1-y2))
    return dist
#判断三个点是否构成三角形
def isTriangle(x1,y1,x2,y2,x3,y3):
    flag = ((x1-x2)*(y3-y2) - (x3-x2)*(y1-y2)) != 0
    return flag

def main():
    print(‘输入三个坐标点（x,y）:‘)
    x1,y1 = eval(input(‘坐标点1（x1,y1）=‘))
    x2, y2 = eval(input(‘坐标点2（x2,y2）=‘))
    x3, y3 = eval(input(‘坐标点3（x3,y3）=‘))
    #判断三个点是否构成三角形
    if(isTriangle(x1,y1,x2,y2,x3,y3)):
        ##计算三角形周长
        perim = distance(x1,y1,x2,y2)+distance(x2,y2,x3,y3)+distance(x3,y3,x1,y1)
        print(‘该三角形周长为：{:.2f}‘.format(perim))
    else:
        print(‘三个点无法构成三角形‘)

main()

def addInterest(balances,rate):
    for i in range(len(balances)):
        balances[i] = balances[i] * (1+rate)
def test():
    amounts = [1000,500,1200,789]
    rate = 0.05
    addInterest(amounts,rate)
    print(amounts)
test()  ##[1050.0, 525.0, 1260.0, 828.45]