20191114Python naming rules

Naming rules:

module_name, package_name, ClassName, method_name, ExceptionName, function_name, GLOBAL_VAR_NAME, instance_var_name, function_parameter_name, local_var_name

Module name: module_name

Package name: package_name

Class Name: ClassName

Method name: method_name

Abnormal name: ExceptionName

Function name: function_name

Global variable names: GLOBAL_VAR_NAME

Examples of variable names: instance_var_name

Function Parameter name: function_parameter_name

Local variable names: local_var_name