input: def get_average_salary(filename: str) -> float:
      """ Read the salary.csv file, compute the average salary, and return it.
      >>> get_average_salary('salary.csv')
      2000.0
      """
output:     
      with open(filename, 'r') as file:
          total_salary = 0.0
          count = 0
          for line in file:
              salary = float(line.strip())
              total_salary += salary
              count += 1
          return total_salary / count if count > 0 else 0.0
  