input: Write a function to compute the average salary of people from the dataset 'salary.csv'. The function should take the filename as input and return the average salary calculated from the data.
  assert get_average_salary('salary.csv')==2000.0 
  assert get_average_salary('salary2.csv')==2500.0 
  assert get_average_salary('empty.csv')==0.0
output: def get_average_salary(filename):
      try:
          with open(filename, 'r') as file:
              lines = file.readlines()
              salaries = [float(line.strip()) for line in lines]
              if salaries:
                  return sum(salaries) / len(salaries)
              else:
                  return 0.0
      except FileNotFoundError:
          return 0.0