python get value from dictionary

Obtain a value from the dictionary. This article is reproduced in http://blog.sina.com.cn/s/blog_6be89284010183xm.html Problem: You need to obtain a value from the dictionary. Do not handle exceptions where the key value you need cannot be found in the

recently writes an interface using python, the dictionary is used to obtain the value of a key. The dictionary format returned by multiple interfaces is not fixed and multiple layers of nesting exist. In the dictionary method, no method can be directly achieved, so I wrote

#import int main (int argc, const char * argv[]) {@autoreleasepool {/* Dictionary: NsdictionaryThe difference between the array used to store the data: The dictionary uses key-value methods, unordered2 is the equivalent of using a dictionary to find specific words in a directory3 in the form of Key-

dictionary, it will be an error, so if you do not want an error, you can use the Get and SetDefault methods.>>> a{' A ': 1, ' B ': 2, ' C ': Ten, ' d ': 11}>>> a.setdefault (' C ', None) 10>>> a.setdefault (' W ', 1000) 1000>>> a{' A ': 1, ' B ': 2, ' C ': Ten, ' d ': One, ' W ': 1000}>>> a.get (' e ', ') 20>>> a{' A ': 1, ' B ': 2, ' C ': Ten, ' d ': One, ' W ': 1000}3. Convert two lists to dictionariesUs

Python dictionary key-Value Pair addition and traversal methods, python dictionary Add a key-Value Pair First define an empty dictionary >>> Dic = {} Directly assign values to keys that

DescribeThe Python dictionary (Dictionary) get () function returns the value of the specified key if the value does not return a default value in the dictionary.GrammarGet () method syn

1: The most straightforward method of looping can be divided into traversing key-value pairs and all keys. 2: query using the LINQ method (of course, the corresponding namespace using system. LINQ should be added here) The following is a very simpleCodeExample: Private Void Getdickeybyvalue () {dictionary String , String > DIC = New Dictionary

1: The most straightforward method of looping can be divided into traversing key-value pairs and all keys. 2: query using the LINQ method (of course, the corresponding namespace using system. LINQ should be added here) The following is a simple code example: private void GetDicKeyByValue(){ Dictionary ..... C # dictionary

DescribeThe Python dictionary (Dictionary) items () function returns an array of traversed (key, value) tuples in a list.GrammarThe items () method syntax:Dict.items ()　　Parameters NA. return valueReturns an array of (key, value) tuples that can be traversed.InstanceT

#-*-Encoding=utf-8-*- Import operator #按字典值排序 (the default is ascending) x = {1:2, 3:4, 4:3, 2:1, 0:0} sorted_x = sorted (X.iteritems (), Key=operator.itemgetter (1)) Print sorted_x #[(0, 0), (2, 1), (1, 2), (4, 3), (3, 4)] #如果要降序排序, you can specify Reverse=true sorted_x = sorted (X.iteritems (), Key=operator.itemgetter (1), reverse=true) Print sorted_x #[(3, 4), (4, 3), (1, 2), (2, 1), (0, 0)] #或者直接使用list的reverse方法将sorted_x顺序反转 #sorted_x. Reverse () #取代方法是, use lambda expressions sorted_x = s

Use a dictionary in Python in the following format: dict={key1:value1, Key2;value2 ...} The following format is used when the dictionary value is actually accessed: Dict[key] Multi-key value The multiple-key form of a dictionary