code: 
  
  
  
  """simple docstring"""
  
  
  
  
  from __future__ import annotations
  
  def 		__snake_case		(   SCREAMING_SNAKE_CASE__			:		list[int | float]       )						->     int | float:
  
  
  
  
  
       '''simple docstring'''
  
       if len(SCREAMING_SNAKE_CASE__       ) == 0:
            raise ValueError("find_max() arg is an empty sequence"       )
       _UpperCAmelCase    :			Any              =					nums[0]
       for x in nums:
            if x > max_num:
                 _UpperCAmelCase    :			List[str]              =					x
       return max_num
  
  
  if __name__ == "__main__":
   import doctest
  
   doctest.testmod(verbose=True)
  
style_context: 
  
  
  
  """simple docstring"""
  
  
  
  
  def 		__snake_case		(   SCREAMING_SNAKE_CASE__			:		list       )						->     bool:
  
  
  
  
  
       '''simple docstring'''
  
       if not isinstance(SCREAMING_SNAKE_CASE__		,						SCREAMING_SNAKE_CASE__       ):
            raise ValueError("Input series is not valid, valid series - [1, 2/3, 2]"       )
       if len(SCREAMING_SNAKE_CASE__       ) == 0:
            raise ValueError("Input list must be a non empty list"       )
       if len(SCREAMING_SNAKE_CASE__       ) == 1 and series[0] != 0:
            return True
       _UpperCAmelCase    :			Tuple              =					[]
       _UpperCAmelCase    :			Any              =					len(SCREAMING_SNAKE_CASE__       )
       for i in range(0		,						SCREAMING_SNAKE_CASE__       ):
            if series[i] == 0:
                 raise ValueError("Input series cannot have 0 as an element"       )
            rec_series.append(1 / series[i]       )
       _UpperCAmelCase    :			Dict              =					rec_series[1] - rec_series[0]
       for index in range(2		,						SCREAMING_SNAKE_CASE__       ):
            if rec_series[index] - rec_series[index - 1] != common_diff:
                 return False
       return True
  
  def 		__snake_case		(   SCREAMING_SNAKE_CASE__			:		list       )						->     float:
  
  
  
  
  
       '''simple docstring'''
  
       if not isinstance(SCREAMING_SNAKE_CASE__		,						SCREAMING_SNAKE_CASE__       ):
            raise ValueError("Input series is not valid, valid series - [2, 4, 6]"       )
       if len(SCREAMING_SNAKE_CASE__       ) == 0:
            raise ValueError("Input list must be a non empty list"       )
       _UpperCAmelCase    :			Any              =					0
       for val in series:
            answer += 1 / val
       return len(SCREAMING_SNAKE_CASE__       ) / answer
  
  
  if __name__ == "__main__":
   import doctest
  
   doctest.testmod()
  