数据类型--元祖-蒲公英云

元祖的概念

元组是另一个数据类型，类似于List（列表）。
元组用 “ (‘a’,2,’b’) “ 标识。内部元素用逗号隔开。
元祖内的元素不能二次赋值，相当于只读列表。
元祖、列表和字符串都是序列

序列的两个主要特点是：索引操作符&切片操作符
1、索引操作符让我们可以从序列中抓取一个特定项目。
2、切片操作符让我们能够获取序列的一个切片，即一部分序列。

1 1、想提取字母b，需要用索引
 2 >>> str1='abcde'
 3 >>> str1[1]
 4 'b'
 5  
 6 2、如果想取值到d，需要用切片
 7 >>> str1[1:4]
 8 'bcd'
 9  
10 注意：数字是可取的，但是'：'是必须的

基本操作：

索引
切片
循环
长度
包含

1 #!/usr/bin/env python
 2 # -*- coding:utf8 -*-
 3 
 4 
 5 tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )
 6 tinytuple = (123, 'john')
 7 
 8 print(tuple) # 输出完整元组
 9 print(tuple[0]) # 输出元组的第一个元素
10 print(tuple[1:3]) # 输出第二个至第三个的元素
11 print(tuple[2:]) # 输出从第三个开始至列表末尾的所有元素
12 print(tinytuple * 2) # 输出元组两次
13 print(tuple + tinytuple) # 打印组合的元组
14 
15 
16 返回结果：
17 ('abcd', 786, 2.23, 'john', 70.2)
18 abcd
19 (786, 2.23)
20 (2.23, 'john', 70.2)
21 (123, 'john', 123, 'john')
22 ('abcd', 786, 2.23, 'john', 70.2, 123, 'john')

元祖和列表的区别

1 #!/usr/bin/env python
 2 # -*- coding:utf8 -*-
 3 
 4 
 5 tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )
 6 list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]
 7 
 8 tuple[2] = 1000 # 元组中是非法应用
 9 
10 输出结果：
11 tuple[2] = 1000 # 元组中是非法应用
12 TypeError: 'tuple' object does not support item assignment
13 
14 
15 list[2] = 1000 # 列表中是合法应用
16 
17 显示结果：
18 ['abcd', 786, 1000, 'john', 70.2]

元祖参数：

1 lass tuple(object):
  2     """
  3     tuple() -> empty tuple
  4     tuple(iterable) -> tuple initialized from iterable's items
  5     
  6     If the argument is a tuple, the return value is the same object.
  7     """
  8     def count(self, value): # real signature unknown; restored from __doc__
  9         """ T.count(value) -> integer -- return number of occurrences of value """
 10         return 0
 11 
 12     def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__
 13         """
 14         T.index(value, [start, [stop]]) -> integer -- return first index of value.
 15         Raises ValueError if the value is not present.
 16         """
 17         return 0
 18 
 19     def __add__(self, y): # real signature unknown; restored from __doc__
 20         """ x.__add__(y) <==> x+y """
 21         pass
 22 
 23     def __contains__(self, y): # real signature unknown; restored from __doc__
 24         """ x.__contains__(y) <==> y in x """
 25         pass
 26 
 27     def __eq__(self, y): # real signature unknown; restored from __doc__
 28         """ x.__eq__(y) <==> x==y """
 29         pass
 30 
 31     def __getattribute__(self, name): # real signature unknown; restored from __doc__
 32         """ x.__getattribute__('name') <==> x.name """
 33         pass
 34 
 35     def __getitem__(self, y): # real signature unknown; restored from __doc__
 36         """ x.__getitem__(y) <==> x[y] """
 37         pass
 38 
 39     def __getnewargs__(self, *args, **kwargs): # real signature unknown
 40         pass
 41 
 42     def __getslice__(self, i, j): # real signature unknown; restored from __doc__
 43         """
 44         x.__getslice__(i, j) <==> x[i:j]
 45                    
 46                    Use of negative indices is not supported.
 47         """
 48         pass
 49 
 50     def __ge__(self, y): # real signature unknown; restored from __doc__
 51         """ x.__ge__(y) <==> x>=y """
 52         pass
 53 
 54     def __gt__(self, y): # real signature unknown; restored from __doc__
 55         """ x.__gt__(y) <==> x>y """
 56         pass
 57 
 58     def __hash__(self): # real signature unknown; restored from __doc__
 59         """ x.__hash__() <==> hash(x) """
 60         pass
 61 
 62     def __init__(self, seq=()): # known special case of tuple.__init__
 63         """
 64         tuple() -> empty tuple
 65         tuple(iterable) -> tuple initialized from iterable's items
 66         
 67         If the argument is a tuple, the return value is the same object.
 68         # (copied from class doc)
 69         """
 70         pass
 71 
 72     def __iter__(self): # real signature unknown; restored from __doc__
 73         """ x.__iter__() <==> iter(x) """
 74         pass
 75 
 76     def __len__(self): # real signature unknown; restored from __doc__
 77         """ x.__len__() <==> len(x) """
 78         pass
 79 
 80     def __le__(self, y): # real signature unknown; restored from __doc__
 81         """ x.__le__(y) <==> x<=y """
 82         pass
 83 
 84     def __lt__(self, y): # real signature unknown; restored from __doc__
 85         """ x.__lt__(y) <==> x<y """
 86         pass
 87 
 88     def __mul__(self, n): # real signature unknown; restored from __doc__
 89         """ x.__mul__(n) <==> x*n """
 90         pass
 91 
 92     @staticmethod # known case of __new__
 93     def __new__(S, *more): # real signature unknown; restored from __doc__
 94         """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
 95         pass
 96 
 97     def __ne__(self, y): # real signature unknown; restored from __doc__
 98         """ x.__ne__(y) <==> x!=y """
 99         pass
100 
101     def __repr__(self): # real signature unknown; restored from __doc__
102         """ x.__repr__() <==> repr(x) """
103         pass
104 
105     def __rmul__(self, n): # real signature unknown; restored from __doc__
106         """ x.__rmul__(n) <==> n*x """
107         pass
108 
109     def __sizeof__(self): # real signature unknown; restored from __doc__
110         """ T.__sizeof__() -- size of T in memory, in bytes """
111         pass
112 
113 tuple