class_docstr: Categorical Distribution 
class_docstr_tok: ["Categorical","Distribution"]
docstr: Returns id for the category. 
code: def get_id(self, category):
      """Returns id for the category."""
      if category is None or np.isnan(category):
          return -1
      return self.cat.index(category)
  
imports: from __future__ import absolute_import
  import numpy
  from .distribution import Discrete
  from ..exd import domains
label_desc: Use image node_id 7 for calling the Categorical obj's underlying member method code with example usage: obj.get_id(category) and returns: self, unknown