i am questioning like everything I can't figure out why it is giving me a syntax error

,,,

students = [['Kermit Wade', 27] ,['Hattie Schleusner', 67], ['Ben Ball', 5] ,['William Lee', 2]]

def Select(students, threshold):
 def Convert(lst):
  res = dict()
  for sub in lst:
   res[tuple(sub[:1])] = tuple(sub[1:])
  return res
  def get_key(val):
    for key, value in Convert(students).items():
         if (val,) == value:
             return key
 s=Convert(students)
 def get_key(val):
    for key, value in Convert(students).items():
         if (val,) == value:
             return key
 e=[]
 
 
 for k in range(threshold,100):
  if get_key(k) != None:

   e.append(get_key(k))
   e.append(s.get(get_key(k)))
 z=e
 new_lst= str(set(z)-set(',() {},  ')





Select(students, 50)

,,,

What is wrong with this code My computer is telling me the error is on 550 where it says select(students,50) But I can’t find the problem

>Solution :

If you look at line: 30 you can see there is a missing parentheses. Replace new_lst = str(set(z) - set(',() {}, ') with new_lst = str(set(z) - set(',() {}, ')).