What is 'eovdedn' doing in this function in python ?

num %2 returns False or True, which can be understood as 0 or 1.

Using the slicing notation 'eovdedn'[num % 2::2] we can have the following results:

• If num % 2 equals False (0) :
  'eovdedn'[0::2] = even (returns every 2 characters starting from 0)

• If num % 2 equals True (1) :
  'eovdedn'[1::2] = odd (returns every 2 characters starting from 1)