How do I check if I can write new/lost grammar?

You want to check the grammar and functions affected by the version, such as the trinomial operator from 2.5, or the missing xrange, in 3.x.

I wrote the code with the intention of raising an exception by checking the version (2.4 or less) before using the trigonometric operator while executing the code.

The code works well with 2.5 and higher, Below, you can't even run it in the first place. Could you tell me how to solve it?

import sys
if sys.version_info < (2, 4):
    Rise "Must be greater than 2.5!"
else:
    # Error in 2.4, from 2.5 to ok
    x = 1 if True else 2
    print x

$ ~/bin/python2.4 tern.py 
  File "tern.py", line 5
    x = 1 if True else 2
           ^
SyntaxError: invalid syntax

$ ~/bin/python2.4 tern.py 
Must be greater than 2.5!