Not getting it

def most_classes(teachers):
         counts = []
         max_classes = 0 
         for key in teachers:
             counts.append(len(teachers[key]))

         for value in counts:
             if value > max_classes:
               max_classes = value 

         for key in teachers:
             if max_classes == len(teachers[key]):
               return key

def num_teachers(teach_dict):
  teach_count = 0
  for name in teach_dict:
    teach_count += 1
  return teach_count

def stats(teachers):
  total_stats = []
  for teacher in teachers:
    total_stats.append( [teacher, len(teachers[teacher])] )
  return total_stats

def courses(teachers):
  course = []

  return course