1 def clear(self): # real signature unknown; restored from __doc__ 2 """ D.clear() -> None. Remove all items from D. """ 3 pass
1 #练习1、清空字典（置空） 2 li = { "key1":"value1","key2":"value2"} 3 li.clear() #清空所有 4 print(li) 5 #执行结果： 6 {}
1 def copy(self): # real signature unknown; restored from __doc__ 2 """ D.copy() -> a shallow copy of D """ 3 pass
1 #练习2、浅拷贝 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 dd = li.copy() #浅拷贝 4 print(li) 5 print(dd) 6 #执行结果： 7 { 'key2': 'value2', 'key3': 'value3', 'key1': 'value1'} 8 { 'key2': 'value2', 'key3': 'value3', 'key1': 'value1'}
1 @staticmethod # known case 2 def fromkeys(*args, **kwargs): # real signature unknown 3 """ Returns a new dict with keys from iterable and values equal to value. """ 4 pass
1 #练习3、迭代字符串生成同一值，放到新字典 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 xin = li.fromkeys("key1","444") 4 print(xin) 5 aa = li.fromkeys("ttb","value1") #分别迭代字符串生成同一个值，放在新字典中，与原字典好像没什么关系 6 print(aa) 7 #执行结果： 8 { '1': '444', 'y': '444', 'e': '444', 'k': '444'} 9 { 'b': 'value1', 't': 'value1'}
1 def get(self, k, d=None): # real signature unknown; restored from __doc__ 2 """ D.get(k[,d]) -> D[k] if k in D, else d. d defaults to None. """ 3 pass
1 #练习4、获取指定键的值 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 aa = li.get("key2") #获取指定键的值 4 print(aa) 5 #执行结果 6 value2
1 def items(self): # real signature unknown; restored from __doc__ 2 """ D.items() -> a set-like object providing a view on D's items """ 3 pass
1 #练习5、获取字典所有内容 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 aa = li.items() #获取字典所有 4 print(aa) 5 #执行结果： 6 dict_items([('key1', 'value1'), ('key3', 'value3'), ('key2', 'value2')])
1 def keys(self): # real signature unknown; restored from __doc__ 2 """ D.keys() -> a set-like object providing a view on D's keys """ 3 pass
1 练习6、获取字典中所有键 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 aa = li.keys() #获取字典所有键 4 print(aa) 5 #执行结果： 6 dict_keys(['key2', 'key3', 'key1'])
1 def pop(self, k, d=None): # real signature unknown; restored from __doc__ 2 """ 3 D.pop(k[,d]) -> v, remove specified key and return the corresponding value. 4 If key is not found, d is returned if given, otherwise KeyError is raised 5 """ 6 pass
1 #练习7、删除指定键 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 aa = li.pop("key2") #删除指定键，连带删除值 4 print(li) 5 #执行结果 6 { 'key1': 'value1', 'key3': 'value3'}
1 def popitem(self): # real signature unknown; restored from __doc__ 2 """ 3 D.popitem() -> (k, v), remove and return some (key, value) pair as a 4 2-tuple; but raise KeyError if D is empty. 5 """ 6 pass
1 #练习8、随机删除键值 2 li = { "key1":"value1","key2":"value2","key3":"value3"} 3 aa = li.popitem() #随机删除指定键，连带删除值 4 print(li) 5 #执行结果：（）随机删掉一个 6 { 'key3': 'value3', 'key1': 'value1'}
1 def setdefault(self, k, d=None): # real signature unknown; restored from __doc__ 2 """ D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D """ 3 pass
1 #练习9、输出指定键值，键不存在则加入字典 2 li = { "key1": "value1", "key2": "value2", "key3": "value3"} 3 aa = li.setdefault("key1","111") # 键存在字典中时，相当于li.get("key1"),不管后面加什么都没影响 4 print(aa) 5 bb = li.setdefault("kkk","111") #键不存在时，输入值，并且该键值会加入到字典中 6 print(bb) 7 print(li) 8 执行结果： 9 value1 10 111 11 { 'key2': 'value2', 'key1': 'value1', 'kkk': '111', 'key3': 'value3'}
1 def update(self, E=None, **F): # known special case of dict.update 2 """ 3 D.update([E, ]**F) -> None. Update D from dict/iterable E and F. 4 If E is present and has a .keys() method, then does: for k in E: D[k] = E[k] 5 If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v 6 In either case, this is followed by: for k in F: D[k] = F[k] 7 """ 8 pass
1 #练习10、更新字典 2 li = { "key1": "value1", "key2": "value2", "key3": "value3"} 3 aa = { "key1":"111","key2":"222"} 4 li.update(aa) #aa是新的，把新的放进旧的，如果键相同则改变值，如果键不同则直接加入 5 print(li) 6 li1 = { "key1": "value1", "key2": "value2", "key3": "value3"} 7 aa1 = { "key1":"111","key2":"222"} 8 aa1.update(li1) 9 print(aa1) 10 #执行结果： 11 { 'key3': 'value3', 'key1': '111', 'key2': '222'} 12 { 'key3': 'value3', 'key1': 'value1', 'key2': 'value2'}
1 def values(self): # real signature unknown; restored from __doc__ 2 """ D.values() -> an object providing a view on D's values """ 3 pass
1 #练习11、输出字典所有值 2 li = { "key1": "value1", "key2": "value2", "key3": "value3"} 3 aa = li.values() #输出字典所有的值 4 print(aa) 5 执行结果： 6 dict_values(['value3', 'value2', 'value1'])