Python's summary of JSON operations (i)

Json

concept:JSON is a lightweight data interchange format.

If we are going to pass objects between different programming languages, we have to serialize the object into a standard format, such as XML, but the better way is to serialize it to JSON, because JSON represents a string that can be read by all languages, easily stored to disk, or transmitted over a network. JSON is not only a standard format, but also faster than XML, and can be read directly in the Web page, very convenient.

format: an unordered collection of ' name '/' values '. {Name 1/value, name 2/value ...}.

Description: You may be reminded of where this format has been seen, yes. In Python, dictionaries also have similar key:value structures. But you can't confuse it.

• The JSON key can only be a string, and Python's dict could be any hash object
• The JSON key can be ordered.
• The JSON key can be repeated
• The values of JSON can only be strings, floating-point numbers, Boolean values, or null, or arrays or objects that they make up.

Encoding-Serialization:

• Dumps: Converting data types to strings
• Dump: Converts a data type into a string and stores it in a file

Decode--Deserialization:

• Loads: Converting a string to a data type
• Load: Convert file to string from data type

Note: All variables are in memory during the program's run. Once the program is finished, the variables will disappear.

So, the process of turning a variable from memory into a storage or transfer is called serialization. in turn, re-reading the variable contents from the serialized object into memory is called deserialization.

1. Dumps: Convert dictionary to string

in [+]: d=dict (name='xjm') in [101]: a=json.dumps (d) in [  102]: aout[102'{"name": "XJM"}'in[ 103 ]: Type (a) out[103]: Str

2. Dump: Writing to the JSON file

In [MAX]: with open ('desktop/j.txt','w') as F:     ...:     a=json.dump (d,f) ...     :print(' file write complete ... ' )     ...: File write complete ...

3. Loads: Read JSON file

In [the]: d=json.loads (a) in [+]: dout[]: {'name'XJM  '}

4. Load: Read JSON file in file

in [+]: with open ('j.txt','rb') as F:     ...:     a =json.load (f) ...     : in [121]: aout[121]: {'name' ' XJM '}

Python's summary of JSON operations (i)