[Tutor] evaluating AND

[Ricardo Aráoz]

Orest Kozyar wrote:
> Given a variable x that can either be None or a tuple of two floats [i.e.
> (0.32, 4.2)], which syntax is considered most appropriate under Python
> coding standards?
> 
> if x and x[0] > 0:
> 	pass
> 
> =====OR=====
> 
> if x:
> 	if x[0] > 0:
> 		pass
> 
> 
> In the first, I'm obviously making the assumption that if the first
> condition evaluates to false, then the second condition won't be evaluated.
> But, is this a good/valid assumption to make?  Is there a more appropriate
> design pattern in Python?
> 
> Thanks!
> Orest
> 

What about exceptions ?

try :
    if x[0] > 0:
	pass          # process the item
except :
    pass              # or do whatever you want if there's no item