class_docstr: Base class to implement a new Prompt.
  
  Inheritors have to override `template` property.
code: def set_var(self, var, value):
      if self._args is None:
          self._args = {}
  
      if var == "dfs":
          self._args["dataframes"] = self._generate_dataframes(value)
      self._args[var] = value
  
file_path: pandas-ai/pandasai/prompts/base.py
imports: from abc import ABC, abstractmethod
  import string
label_desc: Use image node_id 8 for calling the AbstractPrompt obj's underlying member method code with example usage: obj.set_var(var, value) without return types