given a set of integers and a value for which you need to find the nearest one.

def find_nearest(s, target):
  if target in s:
    return target
  
  diff = []
  for val in s:
    diff.append(abs(target - val))
  
  nearest = diff.index(min(diff))
  return s[nearest]
  
find_nearest([1, 2, 3, 4, 5], 6)