input: 
  from typing import Union
  
  def calculate_square_root(number: float) -> Union[float, str]:
      """ Calculate the square root of a given positive number.
      If the number is non-positive, return an error message.
      >>> calculate_square_root(100)
      10.0
      >>> calculate_square_root(0)
      'Error: Input must be a positive number'
      >>> calculate_square_root(-10)
      'Error: Input must be a positive number'
      """
      if number <= 0:
          return 'Error: Input must be a positive number'
      return math.sqrt(number)
  
output:     import math