数字类型转换:
int(1.999) print(int(1.999))
float(1) print(float(1))
int(“123”) print(int(“123”)) “123”是字符串
比较数值大小
eg:num1 =9
num2 = 10
Print((num1>num2)-(num1<num2))
因为num1=9<10 ,所以num1>num2为假,num1<num2为真,即返回0-1,即-1
eg:print(max(num1,num2,num3,... ,numn))
x的y次方
eg:print(pow(x,y))
四舍五入
eg:print(round(3.1415))
Round(x,n)返回浮点数x的四舍五入,如果给出n值,则返回四舍五入到小数点后n位 eg:print(round(3.1415926,3))