class_docstr: ColorMap(pos, color, mapping=ColorMap.CLIP)
  
  ColorMap stores a mapping of specific data values to colors, for example:
  
      | 0.0 → black
      | 0.2 → red
      | 0.6 → yellow
      | 1.0 → white
  
  The colors for intermediate values are determined by interpolating between
  the two nearest colors in RGB color space.
  
  A ColorMap object provides access to the interpolated colors by indexing with a float value:
  ``cm[0.5]`` returns a QColor corresponding to the center of ColorMap `cm`.
docstr: Convenient shorthand access to palette colors 
docstr_tok: ["Convenient","shorthand","access","to","palette","colors"]
code: def __getitem__(self, key):
      """Convenient shorthand access to palette colors"""
      if isinstance(key, int):  # access by color index
          return self.getByIndex(key)
      # otherwise access by map
      try:  # accept any numerical format that converts to float
          float_idx = float(key)
          return self.mapToQColor(float_idx)
      except ValueError:
          pass
      return None
  
imports: from collections.abc import Callable, Sequence
  from os import listdir, path
  import numpy
  from .functions import clip_array, clip_scalar, colorDistance, eq, mkColor
  from .Qt import QtCore, QtGui
label_desc: Use image node_id 4 for calling the ColorMap obj's underlying member method code with example usage: obj.__getitem__(key) and returns: None, self, self