python作为计算器(数学用法)

蔚落 2021-09-30 16:46 240阅读 0赞

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

补充:如果想保留位数需要用到round函数（如果不指定的话默认取整）

>>> print(100/10)
    10.0
    >>> print(round(100/10))
    10
    >>> print(round(100/10,3))
    10.0
    >>> print(round(100/3,3))
    33.333

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

转载于:https://www.cnblogs.com/qlqwjy/p/8450093.html