kvloader.py

kv_pattern = re.compile(r'\w+\.[\w\.]+\w\=.+')
macro_pattern = re.compile(r'\-\-\w[\w\-]+')

class KeyValueConfigLoader(CommandLineConfigLoader):
    """A config loader that loads key value pairs from the command line.

    This allows command line options to be gives in the following form::
    
        ipython Global.profile="foo" InteractiveShell.autocall=False
    """

    def __init__(self, argv=None, shortnames=None, macros=None):
        """Create a key value pair config loader.

        Parameters
        ----------
        argv : list
            A list that has the form of sys.argv[1:] which has unicode
            elements of the form u"key=value". If this is None (default),
            then sys.argv[1:] will be used.
        shortnames : dict
            A dict of aliases for configurable traits.
            Keys are the short aliases, Values are the resolved trait.
            Of the form: `{'shortname' : 'Configurable.trait'}`
        macros : dict
            A dict of macros, keyed by the name of the macro, with
            Configurables (or dicts) for values.

        Returns
        -------
        config : Config
            The resulting Config object.

        Examples
        --------

            >>> from IPython.config.loader import KeyValueConfigLoader
            >>> cl = KeyValueConfigLoader()
            >>> cl.load_config(["foo='bar'","A.name='brian'","B.number=0"])
            {'A': {'name': 'brian'}, 'B': {'number': 0}, 'foo': 'bar'}
        """
        if argv is None:
            argv = sys.argv[1:]
        self.argv = argv
        self.shortnames = shortnames or {}
        self.macros = macros or {}

    def load_config(self, argv=None, shortnames=None, macros=None):
        """Parse the configuration and generate the Config object.

        Parameters
        ----------
        argv : list, optional
            A list that has the form of sys.argv[1:] which has unicode
            elements of the form u"key=value". If this is None (default),
            then self.argv will be used.
        shortnames : dict
            A dict of aliases for configurable traits.
            Keys are the short aliases, Values are the resolved trait.
            Of the form: `{'shortname' : 'Configurable.trait'}`
        macros : dict
            A dict of macros, keyed by the name of the macro, with
            Configurables (or dicts) for values.
        """
        from IPython.config.configurable import Configurable

        self.clear()
        if argv is None:
            argv = self.argv
        if shortnames is None:
            shortnames = self.shortnames
        if macros is None:
            macros = self.macros

        for item in argv:
            if kv_pattern.match(item):
                lhs,rhs = item.split('=',1)
                # Substitute longnames for shortnames.
                if lhs in shortnames:
                    lhs = shortnames[lhs]
                exec_str = 'self.config.' + lhs + '=' + rhs
                try:
                    # Try to see if regular Python syntax will work. This
                    # won't handle strings as the quote marks are removed
                    # by the system shell.
                    exec exec_str in locals(), globals()
                except (NameError, SyntaxError):
                    # This case happens if the rhs is a string but without
                    # the quote marks.  We add the quote marks and see if
                    # it succeeds. If it still fails, we let it raise.
                    exec_str = 'self.config.' + lhs + '="' + rhs + '"'
                    exec exec_str in locals(), globals()
            elif macro_pattern.match(item):
                # trim leading '--'
                m = item[2:]
                if m in macros:
                    # update self.config with Config:
                    self.config.update(macros[m])
                else:
                    raise ValueError("Invalid argument: %r"%item)
            else:
                raise ValueError("Invalid argument: %r"%item)
        return self.config