Hooks make arbitrary transformations to entry data dicts.  Every entry data dict generated by an importer is run through every hook before being output.

``__init__(config)``

  Initializes the hook with the user's configuration.

``run(entry_data)``

Templates

~~~~~~~~~

Templates receive entry data dicts and format them into final output entries.

            else:

                out_file = exit_stack.enter_context(output_path.open('a'))

            for importer, template in importers:

                default_date = self.config.get_default_date()

                in_file.seek(0)

                for entry_data in importer(in_file):

                    for hook in self.hooks:

                        hook.run(entry_data)

                            break

                    else:

                        print(template.render(**entry_data), file=out_file, end='')

    def import_path(self, in_path):

        if in_path is None:

            raise errors.UserInputFileError("only seekable files are supported", '<stdin>')

        with in_path.open(errors='replace') as in_file:

        try:

            date = entry_data['date']

        except KeyError:

            pass

        else:

            if not self.config.date_in_want_range(date):

    (datetime.date(2016, 12, 1), None, datetime.date(2016, 11, 30), False),

])

def test_filter_by_date(entry_date, start_date, end_date, allowed):

    entry_data = {'date': entry_date}

    hook = filter_by_date.FilterByDateHook(DateRangeConfig(start_date, end_date))

    hook.run(entry_data)

class DefaultDateConfig:

    ONE_DAY = datetime.timedelta(days=1)

    def __init__(self, start_date=None):

        if start_date is None: