初识元祖
| 标准类型 |
| 数字 |
| 字符串 |
| 列表 |
| 字典 |
| 元组 |
定义：与列表类似，只不过［］改成（）
特性：
1.可存放多个值
2.不可变
3.按照从左到右的顺序定义元组元素，下标从0开始顺序访问，有序
元祖的创建
ages = (11, 22, 33, 44, 55)
或
ages = tuple((11, 22, 33, 44, 55))
顺序及下标图示
元祖的常用操作
索引
切片
循环
长度
包含
元祖的特性详解
1.可存放多个值
如果元祖中只有一个值
t = (1,) t = (1) #<==>t = 1
元祖中不仅可以存放数字、字符串，还可以存放更加复杂的数据类型
2.不可变
元祖本身不可变，如果元祖中还包含其他可变元素，这些可变元素可以改变
元祖相关知识拾遗
字典中遇到的tuple
1.字典的定义
元祖可以作为字典的key：
dic = {(‘alex‘,‘male‘):‘v1‘,(‘wusir‘,‘male‘):‘v2‘}
print(dic)
字典定义可以用到元祖：
person = dict(([‘name‘,‘苑昊‘],[‘文周‘,18])) person = dict(((‘name‘,‘苑昊‘),(‘文周‘,18))) print(person)
2.字典的items方法，将字典中的每一项作为元祖返回
dic = {‘k1‘:‘v1‘,‘k2‘:‘v2‘}
print(dic.items())
#dict_items([(‘k1‘, ‘v1‘), (‘k2‘, ‘v2‘)])
再讲循环
dic = {‘key1‘:‘value1‘,‘key2‘:‘value2‘}
for key,value in dic.items():
print(key,value)
元祖的工厂函数
class tuple(object): """ tuple() -> empty tuple tuple(iterable) -> tuple initialized from iterable‘s items If the argument is a tuple, the return value is the same object. """ def count(self, value): # real signature unknown; restored from __doc__ """ T.count(value) -> integer -- return number of occurrences of value """ return 0 def index(self, value, start=None, stop=None): # real signature unknown; restored from __doc__ """ T.index(value, [start, [stop]]) -> integer -- return first index of value. Raises ValueError if the value is not present. """ return 0 def __add__(self, *args, **kwargs): # real signature unknown """ Return self+value. """ pass def __contains__(self, *args, **kwargs): # real signature unknown """ Return key in self. """ pass def __eq__(self, *args, **kwargs): # real signature unknown """ Return self==value. """ pass def __getattribute__(self, *args, **kwargs): # real signature unknown """ Return getattr(self, name). """ pass def __getitem__(self, *args, **kwargs): # real signature unknown """ Return self[key]. """ pass def __getnewargs__(self, *args, **kwargs): # real signature unknown pass def __ge__(self, *args, **kwargs): # real signature unknown """ Return self>=value. """ pass def __gt__(self, *args, **kwargs): # real signature unknown """ Return self>value. """ pass def __hash__(self, *args, **kwargs): # real signature unknown """ Return hash(self). """ pass def __init__(self, seq=()): # known special case of tuple.__init__ """ tuple() -> empty tuple tuple(iterable) -> tuple initialized from iterable‘s items If the argument is a tuple, the return value is the same object. # (copied from class doc) """ pass def __iter__(self, *args, **kwargs): # real signature unknown """ Implement iter(self). """ pass def __len__(self, *args, **kwargs): # real signature unknown """ Return len(self). """ pass def __le__(self, *args, **kwargs): # real signature unknown """ Return self<=value. """ pass def __lt__(self, *args, **kwargs): # real signature unknown """ Return self<value. """ pass def __mul__(self, *args, **kwargs): # real signature unknown """ Return self*value.n """ pass @staticmethod # known case of __new__ def __new__(*args, **kwargs): # real signature unknown """ Create and return a new object. See help(type) for accurate signature. """ pass def __ne__(self, *args, **kwargs): # real signature unknown """ Return self!=value. """ pass def __repr__(self, *args, **kwargs): # real signature unknown """ Return repr(self). """ pass def __rmul__(self, *args, **kwargs): # real signature unknown """ Return self*value. """ pass
