class_docstr: Base class for magic line parsers, designed for forgiving parsing
  of keyword lists.
docstr: Strip out any leading/training commas from the token
docstr_tok: ["Strip","out","any","leading\/training","commas","from","the","token"]
code: def _strip_commas(cls, kw):
      "Strip out any leading/training commas from the token"
      kw = kw[:-1] if kw[-1] == "," else kw
      return kw[1:] if kw[0] == "," else kw
  
imports: from itertools import groupby
  import numpy
  import param
  import pyparsing
  from ..core.options import Cycle, Options, Palette
  from ..core.util import merge_option_dicts
  from ..operation import Compositor
  from .transform import dim
label_desc: Use image node_id 1 for calling the Parser obj's underlying member method code with example usage: obj._strip_commas(cls, kw) and returns: unknown