组合数据类型（元组）

1，创建元组

tup1 = ('physics', 'chemistry', 1997, 2000);               # 可以是任基本数据类型构成
tup2 = (1, 2, 3, 4, 5 );                # 纯数字
tup3 = "a", "b", "c", "d"               # 可以不加括号
tup4 = (50,)                            # 元组中只包含一个元素时，需要在元素后面添加逗号

2，基本操作

a，连接

tup1 = ('physics', 'chemistry', 1997, 2000);
tup2 = (1,2,3,4)
print (tup1+tup2)
>>>('physics', 'chemistry', 1997, 2000, 1, 2, 3, 4)

　　b，判断

tup1 = ('physics', 'chemistry', 1997, 2000);
a = 'physics'
print (a in tup1)
>>>True

　　c，复制

tup1 = ('physics', 'chemistry', 1997, 2000);
print (tup1*2)
>>>('physics', 'chemistry', 1997, 2000, 'physics', 'chemistry', 1997, 2000)

d，索引

tup1 = ('physics', 'chemistry', 1997, 2000);
print (tup1[0], tup2[2])
>>>'physics'
1997

　　b，切片

tup1 = ('physics', 'chemistry', 1997, 2000);
print (tup1[0：2])
>>>('physics', 'chemistry')

　　e，步长

tup1 = ("physics","chemistry",1997,2000,1800,"english");
print (tup1[0:4:2])                  # 0代表索引起始值，4代表索引结束值，2为步长
print (tup1[::2])                    # 以2为步长，截取整个列表
print (tup1[1::2])                   # 1为索此起始值，2为步长截取整个列表
>>>('physics', 1997)
('physics', 1997, 1800)
('chemistry', 2000, 'english')

3，常用功能

a，统计个数

tup1 = ("physics","chemistry",1997,2000,1800,"english");
a = len(tup1)                        # 计算元组内元素个数             
print （a）
>>>6

　　b，最大值

tup1 = ("physics","english","chemistry");
print (max(tup1))             # 使用该函数时，元组内元素必须统一数据类型      
>>>physics

　　c，最小值

tup1 = ("physics","english","chemistry");
print (min(tup1))               # 使用该函数时，元组内数据类型必须统一
>>>chemistry

　　d，数据转换

tup1 = ["physics","english","chemistry"]
print (tup1)
print (tuple(tup1))
>>>['physics', 'english', 'chemistry']               # 此数据类型为列表
('physics', 'english', 'chemistry')                       # 此数据类型为元组