parameters: (*k)
return_statement: return do_subst
docstring: register a substitution function
docstring_summary: register a substitution function
docstring_tokens: register a substitution function
function: def subst(*k):
  	"""register a substitution function"""
  	def do_subst(fun):
  		for x in k:
  			try:
  				all_modifs[x].append(fun)
  			except KeyError:
  				all_modifs[x] = [fun]
  		return fun
  	return do_subst
function_tokens: def subst ( * k ) : def do_subst ( fun ) : for x in k : try : all_modifs [ x ] . append ( fun ) except KeyError : all_modifs [ x ] = [ fun ] return fun return do_subst