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Test drive OpenSesame 3.2 "Kafkaesque Koffka" with many new features!

edited December 2017 in OpenSesame

OpenSesame 3.2 is currently under development and should not be used in production!

The next major series of OpenSesame will be 3.2 Kitschy Kuhn. This update will bring several awesome new features, which are described below. For more information, see:

Pre-release packages and Python wheel:

Pre-release repository for Ubuntu:

sudo add-apt-repository ppa:smathot/opensesame-kuhn # only for testing 3.2
sudo add-apt-repository ppa:smathot/cogscinl
sudo apt-get update
sudo apt-get install opensesame

Changes in 3.2

OpenSesame 3.2 brings several major improvements that make it even easier to develop experiments. OpenSesame 3.2 is fully backwards compatible with 3.1.

A better, PEP-8-compliant Python API

PEP-8 is a style guide for Python. Much modern Python software follows the PEP-8 guidelines—but, for historical reasons, OpenSesame didn't. As of 3.2, the public API now follows the guideline that the names of classes (and factory functions that generate classes) should be CamelCase, while names of objects and functions should be underscore_case. Practically speaking, this means that you now create Canvas object as follows:

my_canvas = Canvas() # Note the capital C!

Of course, the old underscore_case names are still available as aliases, so backwards compatibility is preserved.

The API for forms has also been simplified. You no longer need to import libopensesame.widgets, and you no longer need to pass exp as the first argument:

form = Form()
button = Button(text=u'Ok!')
form.set_widget(button, (0, 0))

Access and modify Canvas elements

Elements of a Canvas are now objects that can be named, accessed, and modified. This means that you no longer need to redraw an entire canvas to change a single element. For example, you can draw a rotating arm as follows:

my_canvas = Canvas()
my_canvas['arm'] = Line(0, 0, 0, 0)
for x, y in xy_circle(n=100, rho=100):
    my_canvas['arm'].ex = x
    my_canvas['arm'].ey = y

The SKETCHPAD also allows you to name elements.

For more information, see:

Improved support for HTML and non-Latin script

Text is now rendered by Qt, which is a modern library (the same library that is also used for the graphical interface). This means that you can now use real HTML in your text. This also means that left-to-right script and other non-Latin scripts are rendered much better.

Improved form performance

Forms are now much faster when using the psycho and xpyriment backends. This is due to the fact that Canvas elements can now be updated individually, as described above.

Validation of form input

You can now validate the input of a form; that is, you can prevent a form from closing until certain criteria are met. In addition, you can exclude characters as input from TextInput widgets.

For more information, see:


  • I just want to express my disappointment about this update not being called Kinky Kuhn

  • +1 KinkyKuhn

  • I just want to express my disappointment about this update not being called Kinky Kuhn

    If you file a bug report, I'll see what I can do. It would fit nicely with the theme set by Frisky Freud (0.27).

  • The android back-end doesn't work in the 3.2 version

  • @harsh_shukla This was the case in earlier pre-releases. If you download the latest, the droid backend should work again.

  • Thank you!

  • New Version: Problem with renaming variables. If you rename, click enter, the name is deleted.

  • Great update--modifying canvas elements was the only feature I had been missing in the previous version!

    One issue I had with 3.2.0a30 (but I'm not sure if it's a bug): When running a form using a custom slider widget (that I found somewhere in the forums), I'll get:

    exception message: 'Form' object has no attribute 'render'

    as soon as I try to drag the slider. It works fine in 3.1.9.


  • Hi Georg,

    This slider widget is no longer compatible because of the changes to the Canvas object. So I'm afraid it will have to be re-written!


This discussion has been closed.