Yes, I think that should select the right form (the first one). Although you could also try this command if you are in doubt:
Code:
br.select_form(nr=0)
I just had a brief look at the source code of the page and didn't try it out, but I think the string "Invalid email or password" is always included (even if it is not shown). You should remove that to see what happens or find another way to check the login status.
Code:
if 'Invalid email or password' in raw:
raise Exception('Your username and password are incorrect')