十一、基本运算符

算数运算符

比较运算符

赋值运算符

逻辑运算符

身份运算符

算数运算符

1+1

2

1*6

6

1/9

0.1111111111111111

1//1

1

比较运算符

1>1

False

1<2

True

1>=1

True

赋值运算符

m=1
print(m)

1

逻辑运算符

1. and
2. or
3. not

1<=1 and 1>=1#and逻辑条件都要成立才可以

True

#or要的是一个成立就可以了

身份运算符

is比较的是id

x=10
y=10
print(x is y)
print(x == y)

True
True

x=295
y=295
print(x is y)
print(x == y)

False
True

x=295
y=29
print(x is y)
print(x == y)

False
False

id相同值一定相同，值相同的id不一定相同，除小整数池

Python的优先级

想单独运算那个要加括号

1*3 > 2*1

True

2*(96+3)/8

24.75

链式赋值（考试必考）

y,j,k =10, 20 ,30
print(y,j,k)

10 20 30

交叉赋值（考试必考）

x=10
y=20    #现在要求y=10 x=20

x,y=y,x  #这个是交叉赋值
print(x,y)

20 10

解压缩

hobby_list = ['piao','666',2333,999,'handsone','resd','misic','fooball']

_,hobby1,_,_,_,_,hobby2,_=hobby_list#下划线表示值你字典里面有多少个就要有多少个
print(hobby1,hobby2,_)#为什么最后下划线的值是fooball，因为每一次赋值前一个下划线的值就会被后一个的覆盖

666 misic fooball

hobby_list = ['piao','666',2333,999,'handsome','read','piao','666',2333,999,'handsome','read']
hobby1,*a,hobby2 = hobby_list
print(hobby1)
print(hobby2)
print(a)

piao
read
['666', 2333, 999, 'handsome', 'read', 'piao', '666', 2333, 999, 'handsome']

hobby_list = ['piao','666',2333,999,'handsome','read','piao','666',2333,999,'handsome','read']
hobby1,*_,hobby2 = hobby_list


print(_)

['666', 2333, 999, 'handsome', 'read', 'piao', '666', 2333, 999, 'handsome']

hobby_list = ['piao','666']
hobby1,hobby2 = hobby_list
print(hobby1)
print(hobby2)

piao
666