import csv


def get_depts_mapping(csv_filename):
  """ Parameters:
      csv_filename (string): filepath of the campus csv, the csv lists a table of three columns: ID, Dept_code and Department.
      
      1,ACT,"Actuarial Science"
      2,ANT,"Anthropology"

      Returns:
      A dictionary with Department code as key and full Department name as value.
      {'ACT': 'Actuarial Science', 'ANT': 'Anthropology'}
  """
  mapping = {}
  with open(csv_filename) as raw_csv:
    for row in csv.DictReader(raw_csv):
      mapping[row['Dept_code']] = row['Department']
  return mapping