if or elif either true then do something

Question

this is just for academic interest. I encounter the following situation a lot.

either_true = False if x:   ...do something1   either_true = True elif y:   ...do something2   either_true = True if either_true:   ..do something3 

is there any pythonic way of doing it, or in general better programming way of doing it. Basically do something3 executes only if or elif is true.

Answer 1

You could also omit the either_true flag completely if doSomething3 is a single line of code (e.g. a function call):

if x:   ..do something 1   ..do something 3 elif y:   ..do something 2   ..do something 3 

It maintains the nice property of evaluating x and y at most once (and y won't be evaluated if x is true).