字符串，元组，列表，字典之间的拼接
# 字符串拼接
a = '123'
b = '456'
c = a + b # 123456 type:str
# 字符串与整型拼接
a = '123'
b = 456
c = a + str(b) # 123456 type:str
# 元组拼接
a = (1,2,3)
b = (4,5,6)
c = a + b # (1,2,3,4,5,6) type:tuple
# 列表拼接
a = [1,2,3]
b = [4,5,6]
c = a + b # [1,2,3,4,5,6] type:list
# 字典拼接
a = {1:1, 2:2, 3:3}
b = {4:4, 5:5, 6:6}
(b)
c = a # {1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6} type: dict