Ⅳ:运算符

1、算数运算符

print(10 + 3.1)

print(10 + 3)

print(10 / 3) # 结果带小数

print(10 // 3) # 只保留整数部分

print(10 % 3) # 取模、取余数

print(10 ** 3) # 取模、取余数

2、比较运算符: >、>=、<、<=、==、!=

print(10 > 3)

print(10 == 10)

print(10 >= 10)

print(10 >= 3)

name=input('your name: ')

print(name == 'egon')

3、赋值运算符

3.1 =:变量的赋值

3.2 增量赋值:

age = 18

# age += 1 # age=age + 1

# print(age)

age*=3

age/=3

age%=3

age=3 # age=age3

3.3 链式赋值

x=10

y=x

z=y

z = y = x = 10 # 链式赋值

print(x, y, z)

print(id(x), id(y), id(z))

3.4 交叉赋值

m=10
n=20

print(m,n)

交换值

temp=m

m=n

n=temp

print(m,n)

m,n=n,m # 交叉赋值

print(m,n)

3.5 解压赋值

salaries=[111,222,333,444,555]

把五个月的工资取出来分别赋值给不同的变量名

mon0=salaries[0]

mon1=salaries[1]

mon2=salaries[2]

mon3=salaries[3]

mon4=salaries[4]

解压赋值

mon0,mon1,mon2,mon3,mon4=salaries

print(mon0)

print(mon1)

print(mon2)

print(mon3)

print(mon4)

mon0,mon1,mon2,mon3=salaries # 对应的变量名少一个不行

mon0,mon1,mon2,mon3,mon4,mon5=salaries # 对应的变量名多一个也不行

引入*,可以帮助我们取两头的值,无法取中间的值

取前三个值

x,y,z,*_=salaries=[111,222,333,444,555] # *会将没有对应关系的值存成列表然后赋值给紧跟其后的那个变量名,此处为_

print(x,y,z)

print(_)

取后三个值

*_,x,y,z=salaries=[111,222,333,444,555]

print(x,y,z)

x,*_,y,z=salaries=[111,222,333,444,555]

print(x,y,z)

salaries=[111,222,333,444,555]

_,*middle,_=salaries

print(middle)

解压字典默认解压出来的是字典的key

x,y,z=dic={'a':1,'b':2,'c':3}
print(x,y,z)

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转载自www.cnblogs.com/qujiu/p/12423810.html