[Tutor] If - else Vs OR

[Peter Otten]

Manprit Singh wrote:

> Dear all,
> Consider a problem in which there is a list a, which can contain even as
> well as odd numbers.  For Example  a = [2, 3, 4, 6, 8]
> Now  i have to  filter out all even numbers from this list, and make a new
> list a1 that contains all odd numbers . In case,  if the list a does not
> contains any odd number, then the  resultant will be an empty list , this
> resultant list can be made by :
> a1 = [ i for i in a if i%2 !=  0]
> So, a1 will be empty if list a does not contain any odd number , and if
> list a has one or more odd numbers then a1 will contain all those odd
> numbers .
> i have to write a program which will print "Empty List" if a1 is empty and
> print list a1 if a1 is not empty :
> i  am writing 2 solutions to this problem . My question is which one
> method should be preferred
> sol 1) :
> 
> a = [2, 3, 4, 6, 8]
> a1 = [i for i in a if i%2 != 0]
> if a1:
>     print(a1)
> else:
>     print("Empty list")
> 
> sol 2) :
> 
> a = [2, 3, 4, 6, 8]
> a1 = [i for i in a if i%2 != 0]
> print(a1 or "Empty list")

I think they are both fine, as is

(3)

print(a1 if a1 else "Empty list")

Another idea: you might try and simplify the if part of the list 
comprehension.