How to set 2 vector layers into map canvas, pyqgis 3.0

Question

I have 2 shapefiles which I need to lap. The first one is city grid, and the second one representing borders of the city. Anyway, my code is:

extent = QgsRectangle()
layers = []
QgsProject.instance().addMapLayer(layerInput)
extent.combineExtentWith(layerInput)
layers.append(layerInput)
QgsProject.instance().addMapLayer(layerInputShape)
extent.combineExtentWith(layerInputShape)
layers.append(layerInputShape)
canvas.setExtent(extent)
canvas.setLayers(layers)

But for some reason it's not working, I didn't get the error message. :/

Answer 1

I figured it out! This is the solution. :)

extent = QgsRectangle()
layers = []
QgsProject.instance().addMapLayer(layerInputShape)
extent.combineExtentWith(layerInputShape.extent())
layers.append(layerInputShape)
QgsProject.instance().addMapLayer(layerInput)
extent.combineExtentWith(layerInput.extent())
layers.append(layerInput)

I forgot to call extent method. :/ I was looking for an hour to find the mistake and as soon as I posted this question, I realized what is the mistake. :D