Handlers for checkboxes to select various map features

I am developing a plugin for QGIS (a Geographic Information Systems) software which uses Python. I have several functions where each of them is connected to a QCheckbox. So when a checkbox is checked, the associated function then does the following:

• It reads the text of a QComboBox which contains a list of layers.

• Identifies the layer by its name.

• Sets an expression to be used.

• Selects all features which satisfies the expression.

And when the checkbox is unchecked:

• Deselects all features which satisfies the expression.

Is there a way to merge these functions into one or make it more consise?

Here is the code:

```
def score_0():
opp_selectedLayerIndex = self.dockwidget.areaOpporunityMap_combo.currentText()
opp_sel_layer = QgsMapLayerRegistry.instance().mapLayersByName(str(opp_selectedLayerIndex))[0]
# Select all features where "Score" = NULL
expr = QgsExpression( """ "Score" IS NULL """ )
it = opp_sel_layer.getFeatures( QgsFeatureRequest( expr ) )
ids = [i.id() for i in it]
area = 0
if self.dockwidget.score0_checkbox.isChecked():
opp_sel_layer.select( ids )
else:
opp_sel_layer.deselect( ids)

def score_1():
opp_selectedLayerIndex = self.dockwidget.areaOpporunityMap_combo.currentText()
opp_sel_layer = QgsMapLayerRegistry.instance().mapLayersByName(str(opp_selectedLayerIndex))[0]
# Select all features where "Score" = 1
expr = QgsExpression( """ "Score" = 1 OR "Category" = 'Possible' OR "Category" = 'Favourable' """ )
it = opp_sel_layer.getFeatures( QgsFeatureRequest( expr ) )
ids = [i.id() for i in it]
area = 0
if self.dockwidget.score1_checkbox.isChecked():
opp_sel_layer.select( ids )
else:
opp_sel_layer.deselect( ids)

def score_2():
opp_selectedLayerIndex = self.dockwidget.areaOpporunityMap_combo.currentText()
opp_sel_layer = QgsMapLayerRegistry.instance().mapLayersByName(str(

you only have a difference in two places: query and attribute of dockwidget you are going to check against. so you can pass them as parameters to your score function.

def score(self, query, check_attr):    
    opp_selectedLayerIndex = self.dockwidget.areaOpporunityMap_combo.currentText()
    opp_sel_layer = QgsMapLayerRegistry.instance().mapLayersByName(str(opp_selectedLayerIndex))[0]   
    # Select all features where "Score" = NULL
    expr = QgsExpression(query)
    it = opp_sel_layer.getFeatures(QgsFeatureRequest(expr))
    ids = [i.id() for i in it]

    checkbox = self.dockwidget.getattr(check_attr)

    if checkbox.isChecked():
        opp_sel_layer.select(ids)            
    else:  
        opp_sel_layer.deselect(ids)

StackExchange Code Review Q#148003, answer score: 3