There are two ways to personalize the behavior of a PythonX Operator (where X is either 2 or 3): You can either drag the PythonX Operator to the graph canvas and then edit the script of the operator by right-clicking on it and clicking the open script option; or by creating a new operator in the Repository tab and selecting PythonX Operator as the base operator to be extended. The advantage of the second approach is that you can reuse your new operator across many graphs, while in the first approach, the edited script will be specific to the given graph and operator instance.

In more detail, the second approach can be achieved by opening the Repository tab and expanding the Operators section. You can right-click in any subfolder of Operators to create your operator under it. Then click Create Operator. A dialog will open and ask for the operator name, display name, and base operator. Fill in the fields and choose PythonX Operator as the base operator. Then, in the operator editor view, you will be able to create input ports, output ports, tags, configuration parameters, and write your script.