1.增量赋值
+=、-=、*=、%=、**=等等
2.链式赋值
a =1
b =a
c =b
3.交替赋值
m = 10
n = 20
m,n = n,m
m = 20
n =10
4.解压赋值
a,b,c = [1,2,3] print(a,b,c) #1 2 3
a,b,c,*_ = [1,2,3,4,5,6,7] print(a,b,c,_) #1 2 3 [4, 5, 6, 7]