def draw(self):
        self.iv.image.draw(0,0,self.width,self.height)

you can only fit your image or you might like to calculate the screen ratio first...

with Pythonista 3.2 +

#...
        self.iv.image = ui.Image.named('lock_screen.png')

    def draw(self):
      self.iv.image.draw()
#...

it worked for me

edit: btw. leave out the ImageView is also possible

#...
        #self.iv = ImageView()
        #self.iv...
        self.image = ui.Image.named('lock_screen.png')

    def draw(self):
      self.image.draw()
#...

I don't use pytube, but youtube-dl is working pretty well for me.

You only set the action function of your first button (4 times).

b_top1.action = button_tapped

In this function you need to test the self.title (SUM, DIV, ...) if you want to use it for all four operations.

@cvp: For both 😄

I bought the SQLed app for quick checking things. The downside is you have to "share..." the sqlite db between the apps.

Btw. in the PythonCheatSheet is a sqlite section.

import ui   #import needed library

def tap(sender):   #define function before it is called
    print(sender.title)

v = ui.View()
v.frame = (0,0,400,400)
v.name = 'test'

b = ui.Button()
b.title = 'use'
b.action = tap
b.background_color = 'white'
b.border_color = 'blue'
b.border_width = 1
b.corner_radius = 5
b.frame = (10,10,100,32)
v.add_subview(b)

ba = ui.Button()
ba.title = 'buy'
ba.action = tap
ba.background_color = 'white'
ba.border_color = 'blue'
ba.border_width = 1
ba.corner_radius = 5
ba.frame = (110,10,100,32)
v.add_subview(ba)

v.present('sheet')

ui help

ui Tutorial

PhotoTextV2 Class

look for screen scale

app.run(debug=False)