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  • tuple 元组及字典dict

    1 tu = (11,22,33,)#结尾要加逗号
    2 tu = tuple((11,22,33))
    3 tu = tuple([11,22,33])
    4 
    5 l1 = [11,22,33]
    6 tu = tuple(l1)#把列表转换成元组
    7 li = list(tu)#把元组转换成列表

     字典dict:

    dic = {'k1':'v1', 'k2':'v2'}
    dic = dict(k1 = 'v1',k2 = 'v2')
    清空所有元素:
    def clear(self): # real signature unknown; restored from __doc__ """ D.clear() -> None. Remove all items from D. """ pass
    浅拷贝: 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
        @staticmethod # known case
    
    
    例:
    new_dict = dic.fromkeys(['k1','k2'],'v1')
    print(new_dict)
    得:
    {'k2': 'v1', 'k1': 'v1'}
    
    
    如果没有值返回none,不会报错,也可以设置没有值时的默认值

    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
    dic = {'k1':'v1', 'k2':'v2'}
    #print(dic['k1'])
    #print(dic['k2'])
    #print(dic['k3'])
    
    print(dic.get('k1'))
    print(dic.get('k2'))
    print(dic.get('k3','xiaolong'))#等同于print(dic['k3']),如果没有值返回none,不会报错,也可以设置没有值时的默认值
        def items(self): # real signature unknown; restored from __doc__
            """ D.items() -> a set-like object providing a view on D's items """
            pass
    例:
    dic = {'k1':'v1', 'k2':'v2'} print(dic.keys()) print(dic.values()) print(dic.items())#键值对 for k in dic.keys(): print(k) for v in dic.values(): print(v) for k,v in dic.items(): print(k,v)
    得:

    dict_keys(['k2', 'k1'])
    dict_values(['v2', 'v1'])
    dict_items([('k2', 'v2'), ('k1', 'v1')])
    k2
    k1
    v2
    v1
    k2 v2
    k1 v1

     
        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, k, 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
    例:
    dic = {'k1':'v1', 'k2':'v2'} dic.pop('k1')#pop 必须加一个参数 print(dic)
    得:
    {'k2': 'v2'}
    随意拿走一对:
    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, k, 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
    例:
    dic = {'k1':'v1', 'k2':'v2'} #dic['k3'] = 123 dic.setdefault('k3','v3') print(dic)
    得:
    {'k3': 'v3', 'k2': 'v2', 'k1': 'v1'}
        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

     

     实例:

     1 all_list = [11,22,33,44,55,66,77,88,99]
     2 dic  = {}
     3 l1 = []
     4 l2 = []
     5 
     6 for i in all_list:
     7     if i > 66:
     8         l1.append(i)
     9     else:
    10         l2.append(i)
    11 
    12 dic['k1'] = l1
    13 dic['k2'] = l2
    14 
    15 print(dic)

    改写:

     1 dic  = {}
     2 all_list = [11,22,33,44,55,66,77,88,99]
     3 for i in all_list:
     4     if i>66:
     5         if "k1" in dic.keys():
     6             dic['k1'].append(i)
     7         else:
     8             dic['k1'] = [i,]
     9     else:
    10         if "k2" in dic.keys():
    11             dic['k2'].append(i)#第二次进来K2是列表
    12         else:
    13             dic['k2'] = [i,]#第一次11进来、dic = {'k2':[11,]}
    14 print(dic)
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  • 原文地址:https://www.cnblogs.com/mrzuo/p/7083849.html
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