code: def to_hour(num) -> str:
      
      to_str = str(int(num))
      return pd.Timestamp(f'{to_str[:-2]}:{to_str[-2:]}').strftime('%H:%M')
docs: Convert YAML input to hours
  
      Args:
          num: number in YMAL file, e.g., 900, 1700, etc.
  
      Returns:
          str
  
      Examples:
          >>> to_hour(900)
          '09:00'
          >>> to_hour(1700)
          '17:00'