code: def tplot_rename(old_name, new_name):
      
      
      #check if old name is in current dictionary
      if old_name not in pytplot.data_quants.keys():
          print("That name is currently not in pytplot")
          return
      #if old name input is a number, convert to corresponding name
      if isinstance(old_name, int):
          old_name = pytplot.data_quants[old_name].name
           
      #remake dictionary with new name in old name's slot
      d = pytplot.data_quants
      d2 = OrderedDict([(new_name, v) if k == old_name else (k, v) for k, v in d.items()])
      data_quants = d2
      for key in d2:
          data_quants[key].name = key
      
      pytplot.data_quants = data_quants
      return
docs: This function will rename tplot variables that are already stored in memory.  
      
      Parameters:
          old_name : str 
              Old name of the Tplot Variable
          new_name : str
              New name of the Tplot Variable
           
      Returns:
          None
          
      Examples:
          >>> # Rename Variable 1 to Variable 2
          >>> import pytplot
          >>> pytplot.tplot_rename("Variable1", "Variable2")