code: def percent_change(value, decimal_places=1, multiply=True, failure_string='N/A'):
      
      try:
          f = float(value)
          if multiply:
              f = f * 100
      except ValueError:
         return  failure_string
      s = _saferound(f, decimal_places)
      if f > 0:
          return '+' + s + '%'
      else:
          return s + '%'
docs: Converts a floating point value into a percentage change value.
      
      Number of decimal places set by the `precision` kwarg. Default is one.
      
      Non-floats are assumed to be zero division errors and are presented as
      'N/A' in the output.
      
      By default the number is multiplied by 100. You can prevent it from doing
      that by setting the `multiply` keyword argument to False.