class_docstr: A datashading pipeline callback.
  
  Given a declarative specification, creates a callable with the following
  signature:
  
  ``callback(x_range, y_range, width, height)``
  
  where ``x_range`` and ``y_range`` form the bounding box on the viewport,
  and ``width`` and ``height`` specify the output image dimensions.
  
  Parameters
  ----------
  df : pandas.DataFrame, dask.DataFrame
  glyph : Glyph
      The glyph to bin by.
  agg : Reduction, optional
      The reduction to compute per-pixel. Default is ``count()``.
  transform_fn : callable, optional
      A callable that takes the computed aggregate as an argument, and
      returns another aggregate. This can be used to do preprocessing before
      passing to the ``color_fn`` function.
  color_fn : callable, optional
      A callable that takes the output of ``tranform_fn``, and returns an
      ``Image`` object. Default is ``shade``.
  spread_fn : callable, optional
      A callable that takes the output of ``color_fn``, and returns another
      ``Image`` object. Default is ``dynspread``.
  height_scale: float, optional
      Factor by which to scale the provided height
  width_scale: float, optional
      Factor by which to scale the provided width
code: def __init__(
      self,
      df,
      glyph,
      agg=reductions.count(),
      transform_fn=identity,
      color_fn=tf.shade,
      spread_fn=tf.dynspread,
      width_scale=1.0,
      height_scale=1.0,
  ):
      self.df = df
      self.glyph = glyph
      self.agg = agg
      self.transform_fn = transform_fn
      self.color_fn = color_fn
      self.spread_fn = spread_fn
      self.width_scale = width_scale
      self.height_scale = height_scale
  
file_path: datashader/datashader/pipeline.py
imports: from __future__ import annotations
  from toolz import identity
  from .None import transfer_functions
  from .None import reductions
  from .None import core
label_desc: Use image node_id 1 to create a new Pipeline object  with example: obj = Pipeline(df, glyph, agg, transform_fn, color_fn, spread_fn, width_scale, height_scale)