Minor documentation changes

funcargparse/__init__.py

@@ -465,25 +465,64 @@ def append2helpf(self, arg, s):
         return self._as_decorator('append2help', arg, s)
 
     def grouparg(self, arg, my_arg=None, parent_cmds=[]):
+        """
+        Grouper function for chaining subcommands
+
+        Parameters
+        ----------
+        arg: str
+            The current command line argument that is parsed
+        my_arg: str
+            The name of this subparser. If None, this parser is the main
+            parser and has no parent parser
+        parent_cmds: list of str
+            The available commands of the parent parsers
+
+        Returns
+        -------
+        str or None
+            The grouping key for the given `arg` or None if the key does
+            not correspond to this parser or this parser is the main parser
+            and does not have seen a subparser yet
+
+        Notes
+        -----
+        Quite complicated, there is no real need to deal with this function
+        """
         if self._subparsers_action is None:
             return None
         commands = self._subparsers_action.choices
         currentarg = self.__currentarg
+        # the default return value is the current argument we are in or the
+        # name of the subparser itself
         ret = currentarg or my_arg
         if currentarg is not None:
+            # if we are already in a sub command, we use the sub parser
             sp_key = commands[currentarg].grouparg(arg, currentarg, chain(
                 commands, parent_cmds))
             if sp_key is None and arg in commands:
+                # if the subparser did not recognize the command, we use the
+                # command the corresponds to this parser or (of this parser
+                # is the parent parser) the current subparser
                 self.__currentarg = currentarg = arg
                 ret = my_arg or currentarg
             elif sp_key not in commands and arg in parent_cmds:
+                # otherwise, if the subparser recognizes the commmand but it is
+                # not in the known command of this parser, it must be another
+                # command of the subparser and this parser can ignore it
                 ret = None
             else:
+                # otherwise the command belongs to this subparser (if this one
+                # is not the subparser) or the current subparser
                 ret = my_arg or currentarg
         elif arg in commands:
+            # if the argument is a valid subparser, we return this one
             self.__currentarg = arg
             ret = arg
         elif arg in parent_cmds:
+            # if the argument is not a valid subparser but in one of our
+            # parents, we return None to signalize that we cannot categorize
+            # it
             ret = None
         return ret
 
@@ -504,7 +543,7 @@ def parse_known_args(self, args=None, namespace=None):
                     ns_cmd = cmd.replace('-', '_')
                     choices_d[ns_cmd], remainders[ns_cmd] = super(
                         FuncArgParser, self).parse_known_args(
-                            main_args + list(subargs))
+                            list(chain(main_args, subargs)))
             main_ns, remainders[None] = self.__parse_main(main_args)
             for key, val in vars(main_ns).items():
                 choices_d[key] = val