Click events
if event.type == pygame.MOUSEBUTTONDOWN:
print(event.button)
event.button
can equal several integer values:
1 - left click
2 - middle click
3 - right click
4 - scroll up
5 - scroll down
Fetching mouse state
Instead of waiting for an event, you can get the current button state as well:
state = pygame.mouse.get_pressed()
This returns a tuple in the form: (leftclick, middleclick, rightclick)
Each value is a boolean integer representing whether that button is pressed.