Python基础6-元组
Python的元组与列表类似,不同之处在于元组的元素不能修改或删除。
创建元组
>>> tup1 = () #创建空元组 >>> tup2 = (1) >>> type(tup2) <class 'int'> >>> tup3 = (1,) #创建只有一个元素的元组 >>> type(tup3) <class 'tuple'>
不支持增加、修改、删除元组
>>> tup3[1] = 2 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'tuple' object does not support item assignment >>> tup3[0] = 2 Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'tuple' object does not support item assignment >>> del tup3[0] Traceback (most recent call last): File "<stdin>", line 1, in <module> TypeError: 'tuple' object doesn't support item deletion
切片:取多个元素
>>> tup1 = ('Amy','Bob','Cindy','David','Eric') >>> tup1[1:4] ('Bob', 'Cindy', 'David') >>> tup1[:4] ('Amy', 'Bob', 'Cindy', 'David') >>> tup1[1:] ('Bob', 'Cindy', 'David', 'Eric') >>> tup1[::2] ('Amy', 'Cindy', 'Eric') >>> tup1[-2] 'David'
统计
>>> tup1 ('Amy', 'Bob', 'Cindy', 'David', 'Eric') >>> tup1 = ('Amy','Bob','Amy','Bob') >>> tup1.count('Amy') 2 >>> tup1.count('Bob') 2
索引
>>> tup1 ('Amy', 'Bob', 'Amy', 'Bob') >>> tup1.index('Amy') 0 #只返回找个的第一个索引 >>> tup1.index('Bob') 1 >>> tup1.index('Cindy') Traceback (most recent call last): File "<stdin>", line 1, in <module> ValueError: tuple.index(x): x not in tuple
与tuple相关的函数
序号 | 方法及描述 | 实例 |
---|---|---|
1 | len(tuple) 计算元组元素个数。 |
>>> tuple1 = ('Google', 'Runoob', 'Taobao')
>>> len(tuple1)
3
>>>
|
2 | max(tuple) 返回元组中元素最大值。 |
>>> tuple2 = ('5', '4', '8')
>>> max(tuple2)
'8'
>>>
|
3 | min(tuple) 返回元组中元素最小值。 |
>>> tuple2 = ('5', '4', '8')
>>> min(tuple2)
'4'
>>>
|
4 | tuple(seq) 将列表转换为元组。 |
>>> list1= ['Google', 'Taobao', 'Runoob', 'Baidu']
>>> tuple1=tuple(list1)
>>> tuple1
('Google', 'Taobao', 'Runoob', 'Baidu')
|
tuple的内置方法
序号 | 方法 |
---|---|
1 | tuple.index(obj) 从元组中找出某个值第一个匹配项的索引位置 |
2 | tuple.count(obj) 统计某个元素在元组中出现的次数 |
参考链接:http://www.runoob.com/python3/python3-tuple.html