Support date_formats being a string in parse_with_formats() (#523)

dateparser/date.py

@@ -138,6 +138,9 @@ def parse_with_formats(date_string, date_formats, settings):
     :returns: :class:`datetime.datetime`, dict or None
 
     """
+    if isinstance(date_formats, six.string_types):
+        warn(_DateLocaleParser.DATE_FORMATS_ERROR_MESSAGE, FutureWarning)
+        date_formats = [date_formats]
     period = 'day'
     for date_format in date_formats:
         try:

tests/test_date.py

@@ -287,6 +287,15 @@ def test_should_use_last_day_of_month_for_dates_without_day(
                                           month=expected_month,
                                           day=get_last_day_of_month(expected_year, expected_month)))
 
+    @parameterized.expand([
+        param(date_string='25-03-14', date_formats='%d-%m-%y', expected_result=datetime(2014, 3, 25)),
+    ])
+    def test_should_support_a_string_as_date_formats(self, date_string, date_formats, expected_result):
+        self.when_date_is_parsed_with_formats(date_string, date_formats)
+        self.then_date_was_parsed()
+        self.then_parsed_period_is('day')
+        self.then_parsed_date_is(expected_result)
+
     def given_now(self, year, month, day, **time):
         now = datetime(year, month, day, **time)
         datetime_mock = Mock(wraps=datetime)