python-赋值表达式左边、右边的变量数量小结；右边有逗号表达式、左边的逗号表达式

一、左边是变量，右边是变量或常量

1.1 左单右单，最easy的情况

# 左单右单

a = [1,2]
b = [3,4]
print(a)  # [1, 2]
print(b)  # [3, 4]

1.2 左单右多

# 左单右多

tuple1 = [1,2],[3,4]
print(tuple1)  # ([1, 2], [3, 4])

tuple2 = (1,2),(3,4)
print(tuple2)  # ((1, 2), (3, 4))

1.3 左多右单

# 左多右单

a,b = [[1,2],[3,4]]
print(a)  # [1, 2]
print(b)  # [3, 4]

a,b = ((1,2),(3,4))
print(a)  # [1, 2]
print(b)  # [3, 4]

1.4 左多右多

# 左多右多

a,b = [1,2],[3,4]
print(a)  # [1, 2]
print(b)  # [3, 4]

a,b = (1,2),(3,4)
print(a)  # [1, 2]
print(b)  # [3, 4]

二、右边是函数返回值

# 右边是函数返回值，情况实质也可归类于上面四种之一

# 比如函数返回值有多个的情况，下面这个例子就是左单右多
def func(x,y):
    return x+y,x-y

tuple1=func(7,8)
print(tuple1)  # (15, -1)