Python initial-(Multi-Level dictionary), python initial dictionary

Python initial-(Multi-Level dictionary), python initial dictionary

Nested dictionary in the dictionary

Like a json object,

Data = {

"Msg ":{

"Xxx.com": ["a", "B"]

}

}

Data. values (); # print all values, excluding keys

 

Data ["meg"] ["xxx.com"] [1] = c; # The value of B is changed to c.

 

Data. setdefault (key, value); # If this key is not found in the dictionary, a default

Data. update (); # merge the two dictionaries. If there is a crossover, it overwrites them,

Data. items (); # convert the dictionary to a list

NOTE: If fromkeys is used to create a dictionary (Create 3 points), it is actually a type similar to a shallow copy. If there is a multi-layer nested list, it only copies the address, however, this address points to the same memory. If it is modified, it will all change.

 

Loop

For I in data:

Print (I, data (I ))