PyCharm 2022.2 Help

Configure type rendering

During a debugging session, PyCharm shows you information about your variables, classes, threads, frames, and so on in the Debug tool window. In most cases, the default tool window layout ensures clear, comprehensive, and accurate rendering of all the necessary details and provides you with the most commonly used options and actions.

Type renderers are also used in the Python Console and Jupyter Variable View.

Custom type renderers

PyCharm allows you to provide a completely custom display format for various objects during a debugging session. This is done using renderers. A renderer is a special setup associated with a particular type that controls how the instances of this type are displayed in the debugger. This setup is based on custom expressions that provide high level of flexibility for displaying the data.

A renderer in action

Renderers support all types including primitives and arrays. Also, renderers disregard all access modifiers, so you can access any field irrespective of whether it is encapsulated.

Renderers are particularly useful when you are working with custom collections, whose contents aren't easily readable, and you need to identify their contents at a glance.

Add a renderer

  1. Right-click anywhere in the Variables tab and select Customize data views.

  2. In the <control>Python Type Renderers</control> dialog configure the newly created renderer as required.

    Adding a new type renderer

    Apply the changes and preview the updates in the Variables view.

    Type renderers are applied

Renderer properties

Item

Description

Renderer name

The name of the renderer. This name is used for managing renderers and doesn't affect how actual data is displayed.

Apply renderer to objects of type (fully-qualified name)

The object type to which this renderer applies. Enter the fully qualified name of the class.

When rendering a node

This option determines how an object itself is displayed:

  • Use default renderer: displays the object as it would be displayed without this renderer. This is useful if you want to only customize the way the object's contents are displayed.

  • Use following expression: lets you use the return value of some expression for displaying the object. All method calls and member variable access are relative to the rendered instance.

    For example, self.name will use the value of the name parameter for displaying the object.

When expanding a node

This option determines how the contents of an object are displayed when it is expanded.

  • Use default renderer: displays the node children as they would be displayed without this renderer. This is useful if you want to only customize the way the object itself is displayed.

  • Use list of expressions: allows you to specify multiple expressions each providing its own representation of the object's children.

Append default children

Controls whether the fields of the object (that would be normally displayed when no renderer is specified) should appear along with the expression results. This option is only available with Use list of expressions.

Remove a renderer

  1. Right-click anywhere in the Variables tab and select Customize data views.

  2. On the <control>Python Type Renderers</control> tab, select the renderer that you are going to remove and click Remove Delete.

Mute renderers

You can temporarily disable renderers without removing them altogether:

  • To mute a single renderer, right-click anywhere in the Variables tab and select Customize data views. On the <control>Python Type Renderers</control> tab, clear the box against the renderer you are going to mute.

When required, you can unmute the renderers using the same procedure.

Last modified: 17 March 2022