Understanding Python Decorators: Types and a Practical Example

What is a decorator

Decorators add functionality to existing code without altering its original structure.

Four types of Python decorators

1. Function‑decorating function

2. Function‑decorating class

3. Class‑decorating function

4. Class‑decorating class

Practical example

The example shows how to dynamically obtain a test case name and assign it to a fixed parameter pvid in a called class.

Using get_current_function_name(), the code extracts the function name hierarchy; if a name starts with test_, it is set as pvid and passed as a keyword argument.

The decorator usage is illustrated with screenshots showing the output when test case names are test_case_1, test_case_2, and case_1. The results demonstrate that the decorator can pass the test case name to pvid dynamically, while non‑matching names keep the default value pvid_test.

Summary

This article introduced the four types of Python decorators and provided a concrete scenario using a function‑decorating class to dynamically capture and pass test case names.