Python module, serialization module

First, the module

The module is a written function placed in a file, namely the Py file

Types of modules:

① built-in module: When you install the Python interpreter, it's loaded.

② third-party modules, extension modules: Not necessarily not the built-in module is not important, according to user requirements installation and use

③ Custom module: Self-written py file

Second, serialization module

Sequence: list, tuple, string, bytes

Serialization: The process of converting a data type to a string, bytes type is serialization

Scenarios for serializing data types:

① storing a data type in a file

② when a data type is transmitted over the network

Eval and Exec: User input, file read-in, network incoming can not be used, there is a risk, extremely insecure.

Import JSON # importing JSON module

In JSON format, the strings you want are double quotes.

Json.dumps (obj) serialization process, converting to a string

ImportJson#Importing JSON modulesDIC = {'Province':'Guangdong province',' City':'Shenzhen'}s= Json.dumps (DIC)#the process of serializationPrint(S,type (s))#{"Province": "\u5e7f\u4e1c\u7701", "City": "\u6df1\u5733\u5e02"} <class ' str ' >

Json.loads (str) deserialization process, converted to the original type

ImportJson#Importing JSON modulesDIC = {'Province':'Guangdong province',' City':'Shenzhen'}s= Json.dumps (DIC)#the process of serializationDic2 = Json.loads (s)#the process of deserializationPrint(Dic2,type (dic2))#{' Province ': ' Guangdong province ', ' City ': ' Shenzhen '} <class ' Dict ' >

The advantages of JSON:

① all languages are universal.

The disadvantages of JSON:

① only supports very few data types

② constraints on data types are harsh

The key of the ③ dictionary must be a string

④ only supports data types: numbers, strings, lists, dictionaries

Python module, serialization module