input: Write a function to calculate the square root of a given positive number. If the input number is not positive, return an error message. If the input is invalid (e.g., not a number), also return an error message.
  assert calculate_square_root(100)=='Square root of 100 is {math.sqrt(100)}'
  assert calculate_square_root(25)=='Square root of 25 is {math.sqrt(25)}'
  assert calculate_square_root(-1)=='Error: Input must be a positive number'
  assert calculate_square_root('abc')=='Error: Invalid input'
output: import math
  
  def calculate_square_root(num):
      if isinstance(num, (int, float)):
          if num > 0:
              return f'Square root of {num} is {math.sqrt(num)}'
          else:
              return 'Error: Input must be a positive number'
      else:
          return 'Error: Invalid input'