input: from typing import List
  
  def compute_average_salary(filename: str) -> float:
      """
      Compute the average salary from a CSV file containing salary data.
      >>> compute_average_salary('salary.csv')
      2000.0
      """
output:     total_salary = 0.0
      count = 0
      
      with open(filename, 'r') as file:
          for line in file:
              salary = float(line.strip())
              total_salary += salary
              count += 1
      
      return total_salary / count if count > 0 else 0.0