code: def make_open_functions():
      
      # Create shortcut open methods
      if hasattr(str, 'isidentifier'):
          def isidentifier(x):
              return x.isidentifier()
      else:
          IDENTIFIER_REGEX = re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*$')
          isidentifier = IDENTIFIER_REGEX.match
      for plugin_name, plugin in registry.items():
          func_name = 'open_' + plugin_name
          if not isidentifier(func_name):
              # primitive name normalization
              func_name = re.sub('[-=~^&|@+]', '_', func_name)
          if isidentifier(func_name):
              globals()[func_name] = plugin
          else:
              warnings.warn('Invalid Intake plugin name "%s" found.' %
                            plugin_name)
docs: From the current state of ``registry``, create open_* functions