Python数据类型详解(四)字典:dict
发布时间:2020-12-16 20:42:12 所属栏目:Python 来源:网络整理
导读:一.基本数据类型 整数:int 字符串:str(注:t等于一个tab键) 布尔值: bool 列表:list 列表用[] 元祖:tuple 元祖用() 字典:dict 注:所有的数据类型都存在想对应的类列里,元祖和列表功能一样,列表可以修改,元祖不能修改。 二.字典所有数据类型:
一.基本数据类型 整数:int 注:所有的数据类型都存在想对应的类列里,元祖和列表功能一样,列表可以修改,元祖不能修改。 二.字典所有数据类型: 常用操作: 索引、新增、删除、键、值、键值对、循环、长度 class dict(object): """ dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object's (key,value) pairs dict(iterable) -> new dictionary initialized as if via: d = {} for k,v in iterable: d[k] = v dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list. For example: dict(one=1,two=2) """ def clear(self): # real signature unknown; restored from __doc__ """ D.clear() -> None. Remove all items from D. """ pass def copy(self): # real signature unknown; restored from __doc__ """ D.copy() -> a shallow copy of D """ pass @staticmethod # known case def fromkeys(*args,**kwargs): # real signature unknown """ Returns a new dict with keys from iterable and values equal to value. """ pass def get(self,k,d=None): # real signature unknown; restored from __doc__ """ D.get(k[,d]) -> D[k] if k in D,else d. d defaults to None. """ pass def items(self): # real signature unknown; restored from __doc__ """ D.items() -> a set-like object providing a view on D's items """ pass def keys(self): # real signature unknown; restored from __doc__ """ D.keys() -> a set-like object providing a view on D's keys """ pass def pop(self,d=None): # real signature unknown; restored from __doc__ """ D.pop(k[,d]) -> v,remove specified key and return the corresponding value. If key is not found,d is returned if given,otherwise KeyError is raised """ pass def popitem(self): # real signature unknown; restored from __doc__ """ D.popitem() -> (k,v),remove and return some (key,value) pair as a 2-tuple; but raise KeyError if D is empty. """ pass def setdefault(self,d=None): # real signature unknown; restored from __doc__ """ D.setdefault(k[,d]) -> D.get(k,d),also set D[k]=d if k not in D """ pass def update(self,E=None,**F): # known special case of dict.update """ D.update([E,]**F) -> None. Update D from dict/iterable E and F. If E is present and has a .keys() method,then does: for k in E: D[k] = E[k] If E is present and lacks a .keys() method,then does: for k,v in E: D[k] = v In either case,this is followed by: for k in F: D[k] = F[k] """ pass def values(self): # real signature unknown; restored from __doc__ """ D.values() -> an object providing a view on D's values """ pass def __contains__(self,*args,**kwargs): # real signature unknown """ True if D has a key k,else False. """ pass def __delitem__(self,**kwargs): # real signature unknown """ Delete self[key]. """ pass def __eq__(self,**kwargs): # real signature unknown """ Return self==value. """ pass def __getattribute__(self,**kwargs): # real signature unknown """ Return getattr(self,name). """ pass def __getitem__(self,y): # real signature unknown; restored from __doc__ """ x.__getitem__(y) <==> x[y] """ pass def __ge__(self,**kwargs): # real signature unknown """ Return self>=value. """ pass def __gt__(self,**kwargs): # real signature unknown """ Return self>value. """ pass def __init__(self,seq=None,**kwargs): # known special case of dict.__init__ """ dict() -> new empty dictionary dict(mapping) -> new dictionary initialized from a mapping object's (key,value) pairs dict(iterable) -> new dictionary initialized as if via: d = {} for k,v in iterable: d[k] = v dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list. For example: dict(one=1,two=2) # (copied from class doc) """ pass def __iter__(self,**kwargs): # real signature unknown """ Implement iter(self). """ pass def __len__(self,**kwargs): # real signature unknown """ Return len(self). """ pass def __le__(self,**kwargs): # real signature unknown """ Return self<=value. """ pass def __lt__(self,**kwargs): # real signature unknown """ Return self<value. """ 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,**kwargs): # real signature unknown """ Return self!=value. """ pass def __repr__(self,**kwargs): # real signature unknown """ Return repr(self). """ pass def __setitem__(self,**kwargs): # real signature unknown """ Set self[key] to value. """ pass def __sizeof__(self): # real signature unknown; restored from __doc__ """ D.__sizeof__() -> size of D in memory,in bytes """ pass __hash__ = None 三.所有字典数据类型举例 user_info = { 0 :"zhangyanlin","age" :"18",2 :"pythoner" } #获取所有的key print(user_info.keys()) #获取所有的values print(user_info.values()) #获取所有的key和values print(user_info.items()) clear清除所有的内容 user_info.clear() print(user_info) #get 根据key获取值,如果key不存在,可以指定一个默认值 val = user_info.get('age') print(val) #update批量更新 test = { 'a':111,'b':222 } user_info.update(test) print(user_info) 四.索引 #如果没有key,会报错 user_info = { "name" :'zhangyanlin',"age" :18,"job" :'pythoner' } print(user_info['name']) 五.for循环 #循环 user_info = { 0 :"zhangyanlin",2 :"pythoner" } for i in user_info: print(i) #循环输出所有的键入值 for k,v in user_info.items(): print(k) print(v) 以上就是本文的全部内容了,希望对大家熟练掌握Python数据结构能够有所帮助。 (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
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