初識元祖
標準類型 |
數字 |
字符串 |
列表 |
字典 |
元組 |
定義:與列表相似,只不過[]改爲()ide
特性:
函數
1.可存放多個值
2.不可變
3.按照從左到右的順序定義元組元素,下標從0開始順序訪問,有序post
元祖的建立
ages = (11, 22, 33, 44, 55)
或
ages = tuple((11, 22, 33, 44, 55))
順序及下標圖示
元祖的經常使用操做
索引spa
切片 rest
循環code
長度blog
包含索引
元祖的特性詳解
1.可存放多個值ci
若是元祖中只有一個值字符串
t = (1,) t = (1) #<==>t = 1
元祖中不只能夠存放數字、字符串,還能夠存放更加複雜的數據類型
2.不可變
元祖自己不可變,若是元祖中還包含其餘可變元素,這些可變元素能夠改變
元祖相關知識拾遺
字典中遇到的tuple
1.字典的定義
元祖能夠做爲字典的key:
dic = {('alex','male'):'v1',('wusir','male'):'v2'} print(dic)
字典定義能夠用到元祖:
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,將字典中的每一項做爲元祖返回
dic = {'k1':'v1','k2':'v2'} print(dic.items())
#dict_items([('k1', 'v1'), ('k2', 'v2')])
再講循環
dic = {'key1':'value1','key2':'value2'} for key,value in dic.items(): print(key,value)
元祖的工廠函數
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