how to declare dictionary in python

Use of dictionariesThe fields in the real world and the fields in Python are built so that a particular word (key) can be easily traced to find its meaning (value).In some cases, dictionaries are more appropriate than lists:# characterize the game board state, each key is a tuple composed of coordinate values;# Store the number of file changes, using the filename as the key;# Digital Phone/Address BookCreate a list of people and four-bit extension num

traversed (key, value) tuples as a list. Keys ()#returns a dictionary of all keys in a list>>> D1 = {'Addr':{'IP': 127.0.0.1,'Port': 80},'msg': 18}>>>D1.keys () Dict_keys (['msg','Addr']). VALUES ()#returns all values in the dictionary as a list>>> D1 = {'Addr':{'IP': 127.0.0.1,'Port': 80},'msg': 18}>>>d1.values () dict_values ([19, {'IP':'127.0.0.1','Port': 80}]). SetDefault (key, default=none)#similar to

list conversionManual constructionUsing zipDictionary goto list:List (dic) = = Dict.keys ()Dict.keys () dict.values ()Dictionary transfer tuple:Tuple (DIC)--Contains only key valuesDictionary to string:STR (DIC)practice One: Put the string "K1:1|k2:2|k3:3" processed into python the form of a dictionary : {' K3 ': 3, ' K2 ': 2, ' K1 ': 1 string =

In-depth Python (1): dictionary sorting about sort (), reversed (), sorted (), reversedsorted Http://www.cnblogs.com/BeginMan/p/3193081.html I. Sorting of Python 1. reversed () This is easy to understand. The reversed clause is reverse. print list(reversed(['dream','a','have','I']))#['I', 'have', 'a', 'dream'] 2. Confusing sort () and sorted () In

First, the dictionary1, the initialization of the dictionaryA dictionary is a key-value structurein[160]:d={}in[161]:type (d) Out[161]: dictin[166]:d={' A ':1, ' B ': 2}in[167]:dout[167]:{' a ': 1, ' B ': 2}in[180]:d=dict ({"A":0, "B": 1}) in[181]:dout[181]: {' A ':0, ' B ': 1}in[164]:d=dict ([["A", 1],["B", 2] ]) # The elements of an iterative object must be a two-tuple in[165]:dout[165]:{' a ':1, ' B ': 2}in [168]:d=dict.fromkeys (Range (5)) # The i

Original website: http://www.iplaypython.com/jinjie/jj116.htmlLike other python built-in data types, dictionary dict also has some practical ways to do it. Here we are talking about the dictionary deletion method : Clear (), pop (), and Popitem (), the three methods have different functions, the operation method and the return value are not the same. Next, look a

0x 01 Dictionary IntroductionThe child and list are the two most common data types in Python, the dictionary is the data type of the key-value pair (key-value) format, it has the same index as the list, but not the subscript in the list, but the key is used as the index, the value of the key is values, so the dictionary