python-基本运算符（解压缩-必考）

算术运算符

x =10
y =20
print(x+y)

30

print(x-y)

-10

print(x*y)

200

print(x/y)

0.5

print(x%y)#取余

10

print(y//x) #取整

2

print(y**x) #这标识的是20的10次方

10240000000000

比较运算符

a=10
print(a==10)

True

print(a!=10)  #!=标识不等于

False

print(a>9)

True

print(a<9)

False

print(a>=9)

True

print(type(a<=9))

<class 'bool'>

赋值运算符

a=300
print(a)

300

a +=100
print(a)

400

a *=10
print(a)

4000

a /=10
print(a)

400.0

a //=10
print(a)

40.0

逻辑运算符

and 、or、not

and：两个都是true才是true，否则为false

print(2>3 and 3>2)

False

print(4>3 and 3>2)

True

or 是两个之中有一个是true，就是true

print(2>3 or 2>1)

True

print(2>3 or 2>4)

False

not 是不是的意思（很少用）

print(not 2>3 or 1>2)

True

身份运算符(了解)

x = 258
y = 258
print(id(x),id(y))
print(id(x)==id(y))

2956579849680 2956579849136
False

print(x is y)

False

链式赋值（周考必考）

x=y=z=10
print(x,y,z)

10 10 10

交叉赋值 (周考必考)

x=10
y=20
x,y = y,x
print(x,y)

20 10

解压缩 （周考必考）

快速且能一次性拿到多个列表里的值

duan_hobby_list = ['read','run']
hobby1 = duan_hobby_list[0]
hobby2 = duan_hobby_list[1]
print(hobby1,hobby2)

read run

hobby1,hobby2 = duan_hobby_list
print(hobby1,hobby2)

read run

duan_hobby_list1 = ['read','run','sing','football','basketball']
hobby1,hobby2,_,_,_= duan_hobby_list1
print(hobby1,hobby2)

read run

hobby1,hobby2,*_ = duan_hobby_list1  # “*”代表后面所有对应赋值的位置
print(hobby1,hobby2)

read run

hobby1,*_,hobby5 = duan_hobby_list1
print(hobby1,hobby5)

read basketball