Python dict processing and json

The difference between json and dict

The Python dict is a data structure, a data transmission format is JSON. a json is prepared according to some agreed format pure string , it does not have any data structure of the feature. The manifestation of a string of rules dict python and json looks similar, but dict itself is a complete data structure to achieve all their own that some algorithm.
dict the key Python hash may be any subject, json string only. Formally some similar, but json is plain text, not directly operate.
json formatting requirements and can be used as a boundary symbol in double quotes or key values, not to use single quotes, and "key" have to use boundary character (double), but it does not matter dict.
The Key python dict is unique, and the json Key can be repeated.
The python dict can be nested tuple, json, only array.

json and conversion method in python dict where

Import json 
json.loads () # the json data into data dict 
json.dumps () # the data into json data dict 
the json.load () # read json file data, data converted into dict 
The json.dump () # dict json file write data into the data json

write python json

# Read json file, and converted dict 
with Open ( ' XXX.json ' , ' R & lt ' ) AS F: 
    Data = the json.load (F)
 # or: 
Data = the json.load (Open ( ' XXX.json ' , ' R & lt ' ))
 # the dict data into json, json file and written 
with Open ( ' json_data.txt ' , ' W + ' ) aS F: 
    the json.dump (dict_data, F)

data processing python dict

Take the key, the key-value pair:
 # dictionary for the default iteration output only Key 
for K in dict_data:
     Print (K) 

# iteration output Key 
for K in dict_data.keys ():
     Print (K) 

# iteration output value 
for V in dict_data.values ():
     Print (V) 

# iteration output value pairs 
for K, V in dict_data.items ():
     Print (K, V) 

dict CRUD: 
# increase in a key-value pair: 
dd [ ' new_key ' ] = ' XXX ' 

# change key
dd [ ' Key ' ] = ' XX ' 

# delete the key for 
del [ ' Key ' ]   # delete the key dictionary is a first layer 
del [ ' key1 ' ] [ ' key2 ' ] [ ' key3 ' ] # Erasing value pairs nesting in 
dd.pop ( ' Key ' ) # delete the key pair, and returns the corresponding value 

# is determined whether the dictionary format 
isinstance (data, dict)

Python dict processing and json

Guess you like