class_docstr: A ChainMap groups multiple dicts (or other mappings) together
  to create a single, updateable view.
  
  The underlying mappings are stored in a list.  That list is public and can
  accessed or updated using the *maps* attribute.  There is no other state.
  
  Lookups search the underlying mappings successively until a key is found.
  In contrast, writes, updates, and deletions only operate on the first
  mapping.
class_docstr_tok: ["A","ChainMap","groups","multiple","dicts","(","or","other","mappings",")","together","to","create","a","single",",","updateable","view",".","The","underlying","mappings","are","stored","in","a","list",".","That","list","is","public","and","can","accessed","or","updated","using","the","*","maps","*","attribute",".","There","is","no","other","state",".","Lookups","search","the","underlying","mappings","successively","until","a","key","is","found",".","In","contrast",",","writes",",","updates",",","and","deletions","only","operate","on","the","first","mapping","."]
docstr: New ChainMap with a new dict followed by all previous maps.
docstr_tok: ["New","ChainMap","with","a","new","dict","followed","by","all","previous","maps","."]
code: def new_child(self):  # like Django's Context.push()
      "New ChainMap with a new dict followed by all previous maps."
      return self.__class__({}, *self.maps)
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from __future__ import unicode_literals
  import sys
  from abc import ABCMeta
label_desc: Use image node_id 11 for calling the ChainMap obj's underlying member method code with example usage: obj.new_child() and returns: self