Setting direction to clockwise using PyQGIS

Question

I am looking for a way to change the direction of the pie charts of a layer from counter-clockwise to clockwise in QGIS 3. I looked in the docs but I don´t seem to find a way to do this. Does anybody know what I need to do?

I create the pie charts like this:

current_colors = {}  # maps the field names to QColor objects
diagram = QgsPieDiagram()
ds = QgsDiagramSettings()
ds.categoryColors = current_colors.values()
ds.categoryAttributes = current_colors.keys()
ds.categoryLabels = ds.categoryAttributes

dr = QgsLinearlyInterpolatedDiagramRenderer()
max_val = layer.maximumValue(layer.fields().indexFromName(pie_sum_col))
dr.setUpperValue(max_val)
dr.setLowerSize(QSizeF(2, 2))
dr.setUpperSize(QSizeF(40, 40))
dr.setClassificationField(pie_sum_col)
dr.setDiagram(diagram)
dr.setDiagramSettings(ds)
    
layer.setDiagramRenderer(dr)
dls = QgsDiagramLayerSettings()
dls.setPlacement(1)
layer.setDiagramLayerSettings(dls)
layer.triggerRepaint()

Answer 1

QGIS Diagram settings way :

ds = QgsDiagramSettings()
# counter-clockwise direction
ds.setDirection(QgsDiagramSettings.Counterclockwise)
# clockwise direction
ds.setDirection(QgsDiagramSettings.Clockwise)

---

Basic way :

Your current Python dictionnary is :

current_colors = {
    '"field_one"': QColor("#FF0000"),
    '"field_two"': QColor("#00FF00"),
    '"field_three"': QColor("#0000FF"),
}

The result are diagrams in counter-clockwise order. So, just reverse the order of current_colors :

current_colors = {
    '"field_three"': QColor("#0000FF"),
    '"field_two"': QColor("#00FF00"),
    '"field_one"': QColor("#FF0000"),
}

or if you don't want to do this manually :

current_colors = {k: current_colors[k] for k in reversed(current_colors)}

The result will be diagrams in clockwise order.