Python django.utils.functional 模块，lazy() 实例源码

def csrf(request):
    """
    Context processor that provides a CSRF token, or the string 'NOTPROVIDED' if
    it has not been provided by either a view decorator or the middleware
    """
    def _get_val():
        token = get_token(request)
        if token is None:
            # In order to be able to provide debugging info in the
            # case of misconfiguration, we use a sentinel value
            # instead of returning an empty dict.
            return 'NOTPROVIDED'
        else:
            return smart_text(token)
    _get_val = lazy(_get_val, six.text_type)

    return {'csrf_token': _get_val() }

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connection
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(lambda: connection.queries, list)
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        original_kwargs = kwargs.copy()

        class NumberAwareString(resultclass):
            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError('Your dictionary lacks key \'%s\'. '
                            'Please provide it, because it is required to '
                            'determine whether string is singular or plural.'
                            % number)
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
        proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
    return proxy

def override_gettext(real_translation):
    """Replace Django's translation functions with safe versions."""
    translation.gettext = real_translation.gettext
    translation.ugettext = real_translation.ugettext
    translation.ngettext = real_translation.ngettext
    translation.ungettext = real_translation.ungettext
    translation.gettext_lazy = lazy(real_translation.gettext, str)
    translation.ugettext_lazy = lazy(real_translation.ugettext, unicode)
    translation.ngettext_lazy = lazy(real_translation.ngettext, str)
    translation.ungettext_lazy = lazy(real_translation.ungettext, unicode)

def patch_reverse():
    """Overwrite the default reverse implementation.

    Monkey-patches the urlresolvers.reverse function. Will not patch twice.
    """
    global django_reverse, django_reverse_lazy
    if hasattr(settings, 'REVERSE_METHOD') and django_reverse is None:
        django_reverse = urls.reverse
        django_reverse_lazy = urls.reverse_lazy

        module_name, func_name = settings.REVERSE_METHOD.rsplit('.', 1)
        reverse = getattr(importlib.import_module(module_name), func_name)

        urls.reverse = reverse
        urls.reverse_lazy = lazy(reverse, six.text_type)

def get_actions(self):
        resolved = self.RESOLVED.copy()
        resolved['help_text'] = lazy(
            lambda: self.RESOLVED['help_text'] + self.creator_assign_text()
        )
        reopened = self.REOPENED.copy()
        reopened['help_text'] = lazy(
            lambda: self.REOPENED['help_text'] + self.resolver_assign_text()
        )
        verified = self.VERIFIED.copy()
        verified['help_text'] = lazy(
            lambda: self.VERIFIED['help_text'] + self.resolver_assign_text()
        )

        if self.bug:
            state = self.bug.state
        else:
            state = None

        if state == State.NEW:
            return [self.COMMENT, resolved, self.ENTRUSTED]
        elif state == State.ENTRUSTED:
            return [self.COMMENT, resolved]
        elif state in self.RESOLVED_STATES:
            return [self.COMMENT, verified, reopened, self.LIVE, self.CLOSED]
        elif state == State.REOPENED:
            return [self.COMMENT, resolved, self.ENTRUSTED]
        elif state == State.LIVE:
            return [self.COMMENT, reopened, self.CLOSED]
        elif state == State.CLOSED:
            return [self.COMMENT, reopened]
        elif state == State.VERIFIED:
            return [self.COMMENT, reopened, self.LIVE, self.CLOSED]
        elif state is None:
            return [
                {'action': 'create', 'label': 'Create', 'help_text': "Create a bug."},
            ]
        else:
            assert False, 'Unknown state %s' % state

def __init__(self, target_model, filter_name=None, **kwargs):
        super(ModelChooserBlock, self).__init__(**kwargs)
        self._target_model = target_model

        self.filter_name = filter_name

        if self.meta.icon == 'placeholder':
            # Get the icon from the chooser.
            # The chooser may not have been registered yet, depending upon
            # import orders and things, so get the icon lazily
            self.meta.icon = lazy(lambda: self.chooser.icon, str)()

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connections
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(
            lambda: list(itertools.chain(*[connections[x].queries for x in connections])),
            list
        )
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        original_kwargs = kwargs.copy()

        class NumberAwareString(resultclass):
            def __bool__(self):
                return bool(kwargs['singular'])

            def __nonzero__(self):  # Python 2 compatibility
                return type(self).__bool__(self)

            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError(
                            "Your dictionary lacks key '%s\'. Please provide "
                            "it, because it is required to determine whether "
                            "string is singular or plural." % number
                        )
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
        proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
    return proxy

def test_find_item_lazy(self):
        lazy_attribute = lazy(lambda x: x, str)('Test')
        api = ToolbarAPIMixin()
        api.add_link_item(lazy_attribute, None)
        result = api.find_first(LinkItem, name='Test')
        self.assertNotEqual(result, None)
        self.assertEqual(result.index, 0)

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connections
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(
            lambda: list(itertools.chain(*[connections[x].queries for x in connections])),
            list
        )
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        original_kwargs = kwargs.copy()

        class NumberAwareString(resultclass):
            def __bool__(self):
                return bool(kwargs['singular'])

            def __nonzero__(self):  # Python 2 compatibility
                return type(self).__bool__(self)

            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError(
                            "Your dictionary lacks key '%s\'. Please provide "
                            "it, because it is required to determine whether "
                            "string is singular or plural." % number
                        )
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
        proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
    return proxy

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connection
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(lambda: connection.queries, list)
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        original_kwargs = kwargs.copy()

        class NumberAwareString(resultclass):
            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError('Your dictionary lacks key \'%s\'. '
                            'Please provide it, because it is required to '
                            'determine whether string is singular or plural.'
                            % number)
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
        proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
    return proxy

def _lazy_get_settings(opt, ttype, default_value=obj):
    return lazy(_call_getattr, ttype)(opt, default_value)

# Lazyly read configurations to allow @override_settings

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connection
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(lambda: connection.queries, list)
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        original_kwargs = kwargs.copy()

        class NumberAwareString(resultclass):
            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError('Your dictionary lacks key \'%s\'. '
                            'Please provide it, because it is required to '
                            'determine whether string is singular or plural.'
                            % number)
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
        proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
    return proxy

def debug(request):
    """
    Returns context variables helpful for debugging.
    """
    context_extras = {}
    if settings.DEBUG and request.META.get('REMOTE_ADDR') in settings.INTERNAL_IPS:
        context_extras['debug'] = True
        from django.db import connection
        # Return a lazy reference that computes connection.queries on access,
        # to ensure it contains queries triggered after this function runs.
        context_extras['sql_queries'] = lazy(lambda: connection.queries, list)
    return context_extras

def lazy_number(func, resultclass, number=None, **kwargs):
    if isinstance(number, six.integer_types):
        kwargs['number'] = number
        proxy = lazy(func, resultclass)(**kwargs)
    else:
        class NumberAwareString(resultclass):
            def __mod__(self, rhs):
                if isinstance(rhs, dict) and number:
                    try:
                        number_value = rhs[number]
                    except KeyError:
                        raise KeyError('Your dictionary lacks key \'%s\'. '
                            'Please provide it, because it is required to '
                            'determine whether string is singular or plural.'
                            % number)
                else:
                    number_value = rhs
                kwargs['number'] = number_value
                translated = func(**kwargs)
                try:
                    translated = translated % rhs
                except TypeError:
                    # String doesn't contain a placeholder for the number
                    pass
                return translated

        proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
    return proxy