def update(self, template, no_fuzzy_matching=False):
        """Update the catalog based on the given template catalog.

        >>> from babel.messages import Catalog
        >>> template = Catalog()
        >>> template.add('green', locations=[('main.py', 99)])
        >>> template.add('blue', locations=[('main.py', 100)])
        >>> template.add(('salad', 'salads'), locations=[('util.py', 42)])
        >>> catalog = Catalog(locale='de_DE')
        >>> catalog.add('blue', u'blau', locations=[('main.py', 98)])
        >>> catalog.add('head', u'Kopf', locations=[('util.py', 33)])
        >>> catalog.add(('salad', 'salads'), (u'Salat', u'Salate'),
        ...             locations=[('util.py', 38)])

        >>> catalog.update(template)
        >>> len(catalog)
        3

        >>> msg1 = catalog['green']
        >>> msg1.string
        >>> msg1.locations
        [('main.py', 99)]

        >>> msg2 = catalog['blue']
        >>> msg2.string
        u'blau'
        >>> msg2.locations
        [('main.py', 100)]

        >>> msg3 = catalog['salad']
        >>> msg3.string
        (u'Salat', u'Salate')
        >>> msg3.locations
        [('util.py', 42)]

        Messages that are in the catalog but not in the template are removed
        from the main collection, but can still be accessed via the `obsolete`
        member:

        >>> 'head' in catalog
        False
        >>> catalog.obsolete.values()
        [<Message 'head' (flags: [])>]

        :param template: the reference catalog, usually read from a POT file
        :param no_fuzzy_matching: whether to use fuzzy matching of message IDs
        """
        messages = self._messages
        remaining = messages.copy()
        self._messages = odict()

        # Prepare for fuzzy matching
        fuzzy_candidates = []
        if not no_fuzzy_matching:
            fuzzy_candidates = [
                self._key_for(msgid) for msgid in messages
                if msgid and messages[msgid].string
            ]
        fuzzy_matches = set()

        def _merge(message, oldkey, newkey):
            message = message.clone()
            fuzzy = False
            if oldkey != newkey:
                fuzzy = True
                fuzzy_matches.add(oldkey)
                oldmsg = messages.get(oldkey)
                if isinstance(oldmsg.id, basestring):
                    message.previous_id = [oldmsg.id]
                else:
                    message.previous_id = list(oldmsg.id)
            else:
                oldmsg = remaining.pop(oldkey, None)
            message.string = oldmsg.string
            if isinstance(message.id, (list, tuple)):
                if not isinstance(message.string, (list, tuple)):
                    fuzzy = True
                    message.string = tuple(
                        [message.string] + ([u''] * (len(message.id) - 1))
                    )
                elif len(message.string) != self.num_plurals:
                    fuzzy = True
                    message.string = tuple(message.string[:len(oldmsg.string)])
            elif isinstance(message.string, (list, tuple)):
                fuzzy = True
                message.string = message.string[0]
            message.flags |= oldmsg.flags
            if fuzzy:
                message.flags |= set([u'fuzzy'])
            self[message.id] = message

        for message in template:
            if message.id:
                key = self._key_for(message.id)
                if key in messages:
                    _merge(message, key, key)
                else:
                    if no_fuzzy_matching is False:
                        # do some fuzzy matching with difflib
                        matches = get_close_matches(key.lower().strip(),
                                                    fuzzy_candidates, 1)
                        if matches:
                            _merge(message, matches[0], key)
                            continue

                    self[message.id] = message

        self.obsolete = odict()
        for msgid in remaining:
            if no_fuzzy_matching or fuzzy_matches not in msgid:
                self.obsolete[msgid] = remaining[msgid]
        # Make updated catalog's POT-Creation-Date equal to the template
        # used to update the catalog
        self.creation_date = template.creation_date
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/Babel-0.9.6/babel/messages/catalog.py/Catalog.update/swapped operands of `not in`