class_docstr: Stage allows you evaluating mapping at more than one stage
  
  You can evaluate an expression of a variable in a dataframe, and
  later evaluate an expression that modifies the values mapped to
  the scale.
  
  Parameters
  ----------
  start : str | array_like | scalar
      Aesthetic expression using primary variables from the layer
      data.
  after_stat : str
      Aesthetic expression using variables calculated by the stat.
  after_scale : str
      Aesthetic expression using aesthetics of the layer.
class_docstr_tok: ["Stage","allows","you","evaluating","mapping","at","more","than","one","stage","You","can","evaluate","an","expression","of","a","variable","in","a","dataframe",",","and","later","evaluate","an","expression","that","modifies","the","values","mapped","to","the","scale",".","Parameters","--","--","--","--","--","start",":","str","|","array_like","|","scalar","Aesthetic","expression","using","primary","variables","from","the","layer","data",".","after_stat",":","str","Aesthetic","expression","using","variables","calculated","by","the","stat",".","after_scale",":","str","Aesthetic","expression","using","aesthetics","of","the","layer","."]
docstr: Repr for staged mapping
docstr_tok: ["Repr","for","staged","mapping"]
code: def __repr__(self):
      """
      Repr for staged mapping
      """
      # Shorter representation when the mapping happens at a
      # single stage
      if self.after_stat is None and self.after_scale is None:
          return f"{repr(self.start)}"
      if self.start is None and self.after_scale is None:
          return f"after_stat({repr(self.after_stat)})"
      if self.start is None and self.after_stat is None:
          return f"after_scale({repr(self.after_scale)})"
      return (
          f"stage(start={repr(self.start)}, "
          f"after_stat={repr(self.after_stat)}, "
          f"after_scale={repr(self.after_scale)})"
      )
  
file_path: plotnine/plotnine/mapping/evaluation.py
imports: from __future__ import annotations
  import numbers
  import typing
  import numpy
  import pandas
  import pandas.api.types
  from ..exceptions import PlotnineError
label_desc: Use image node_id 2 for calling the stage obj's underlying member method code with example usage: obj.__repr__() and returns: str, repr, str, repr, str, repr, str, repr, str, repr, str, str, repr, str