old_contents: courselist = [{'department': 'MATH', 'number': 417, 'crn': 65075},
                {'department': 'MATH', 'number': 484, 'crn': 30809},
                {'department': 'MATH', 'number': 347, 'crn': 34395},
               ]
  
  
new_contents: courselist = [{'department': 'MATH', 'number': 417, 'crn': 65075},
                {'department': 'MATH', 'number': 484, 'crn': 30809},
                {'department': 'MATH', 'number': 347, 'crn': 34395},
                {'department': 'MATH', 'number': 124, 'crn': 45900},
               ]
  
  
  
subject: Update courselist.py