test_dict_02 = {'key1': 'welcome', 'key2': 'to', 'key3': 'Guangzhou'} test_dict_03 = {} test_dict_02['key1'] = '欢迎' # 原字典存在即替换 test_dict_02['key4'] = '中国' # 原字典不存在则添加 test_dict_03['key1'] = '欢迎' # 空字典直接添加 print(test_dict_02) ...
方法一:直接遍历速度快 forkeyin_dict:pass 方法二:iterkeys()速度快 for_intestDict.iterkeys():pass 方法三:keys()速度慢因为keys()须要形成一个列表,构建一个列表对于一个大的dict开销是很大的。 for_intestDict.keys():pass 时间对比: importtimeit DICT_SIZE= 100*10000testDict=dict()foriinrange(DICT...
for keys in dict.keys(): print(keys) #遍历出所有的value for value in dict.values(): print(value) #遍历出 for key,value in dict.items(): print(key+':'+value) #结果: k1 k2 k3 v1 v2 v3 k1:v1 k2:v2 k3:v3 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 1...
for key1 in dict: for key2 in dict[key1]: print(key1) print(key2) print(dict[key1][key2]) 字典key和value的排序 这里使用sorted函数 按照key进行排序 >>>dict={'apple':'苹果','banana':'香蕉','pear':'梨'}>>>sorted(dict.keys())['apple','banana','pear']>>>sorted(dict.keys()...
del dict_test['Number'] 2.遍历字典 dict_test = { 'First_name': 'Alex', 'Last_name': 'Shaw', 'Age': '27', } for key,value in dict_test.items(): #items()返回一个key-value对列表,for循环每次将一个key-value对存储到指定的变量 ...
for _ in testDict.keys(): pass def test2(): for _ in testDict: pass d...
dict(['ab', 'cd']) bdict = dict([('name', 'bob'),('age', 25)]) {}.fromkeys(['zhangsan', 'lisi', 'wangwu'], 11) for key in bdict: print('%s: %s' % (key, bdict[key])) print("%(name)s: %(age)s" % bdict) ...
for k in d.keys()操作对应的是PyDictKeys_Type里的dictkeys_iter函数,返回了这个DictView视图对应的dict的key的iterator,类型为PyDictIterKey_Type。在迭代遍历时候,会一直调用PyDictIterKey_Type里定义的dictiter_iternextkey执行迭代过程中的next操作,从而一个个地获得dict里所有key。
items(), key=lambda item: item[1], reverse=reverse ) self.clear() self.update(sorted_items) In this example, you inherit from the built-in dict class. On top of the class’s default functionality, you add two new methods for sorting the dictionary by keys and values in place, ...
Dictionaries can be used for performing very fast look-ups on unordered data. 关于词典,需要注意的一个关键方面是它们不是序列,因此不保持任何类型的左右顺序。 A key aspect to be aware about regarding dictionaries is that they are not sequences, and therefore do not maintain any type of left-righ...