# Parameter Trees

Parameter trees are a system for handling hierarchies of parameters while automatically generating one or more GUIs to display and interact with the parameters. This feature is commonly seen, for example, in user interface design applications which display a list of editable properties for each widget. Parameters generally have a name, a data type (int, float, string, color, etc), and a value matching the data type. Parameters may be grouped and nested to form hierarchies and may be subclassed to provide custom behavior and display widgets.

PyQtGraph’s parameter tree system works similarly to the model-view architecture used by some components of Qt: Parameters are purely data-handling classes that exist independent of any graphical interface. A ParameterTree is a widget that automatically generates a graphical interface which represents the state of a haierarchy of Parameter objects and allows the user to edit the values within that hierarchy. This separation of data (model) and graphical interface (view) allows the same data to be represented multiple times and in a variety of different ways.

For more information, see the ‘parametertree’ example included with pyqtgraph and the API reference

- ParameterTree API Reference
  - Parameter
  - ParameterTree
  - Built-in Parameter Types
  - ParameterItem