1.基本的加减乘除与取余运算
>>> print(5+10) 15 >>> print(5-10) -5 >>> print(5*10) 50 >>> print(10/5) 2.0 >>> print(5%3) 2
2.求n次方与求平方根
>>> print(5%3) 2 >>> print(5**3) 125 >>> print(125**(1/3)) 5.0 >>> print(2**4) 16 >>> print(16**(1/2)) 4.0 >>>
3.math函数库的使用
引入math库并查看PI的值
>>> import math >>> math.pi 3.141592653589793
(1)求正弦余弦函数
>>> math.sin(math.pi/2) 1.0 >>> math.cos(math.pi/4) 0.7071067811865476 >>> math.tan(math.pi/4) 0.9999999999999999 >>>
(2)上取整与下取整
>>> math.floor(5.225) 5 >>> math.ceil(5.225) 6
练习:一道应用题
苹果5元一斤，葡萄15元一斤，卖了一斤苹果2.5斤葡萄，问总共花了多少钱?
解:
>>> #苹果花费 ... >>> #葡萄花费 ... >>> print(5*1) 5 >>> print(15*2.5) 37.5 >>> #总花费 ... >>> print(5+37.5) 42.5
解法二:
>>> apple_price = 5 >>> apple_weight = 1 >>> putao_price = 15 >>> putao_weight = 2.5 >>> #苹果花费 ... print(apple_price*apple_weight) 5 >>> #葡萄花费 ... print(putao_price*putao_weight) 37.5 >>> #总花费 ... print(5+37.5) 42.5 >>>
>>> putao_toast = putao_price*putao_weight >>> apple_toast = apple_price*apple_weight >>> print(putao_toast + apple_toast) 42.5
解法三:利用增强的格式化字符串函数 format
>>> "葡萄的总价是{},苹果的总价是{},总共花费{}".format(putao_toast,apple_toast,pu tao_toast+apple_toast) ‘葡萄的总价是37.5,苹果的总价是5,总共花费42.5‘
{}代表取参数，有几个{},传几个参数，按顺序取参数
