[2.0.x] Fixed #28947 -- Fixed crash when coercing a translatable URL pattern to str.

Regression in df41b5a05d.

Backport of 01384ce36c from master

django/urls/resolvers.py

@@ -183,7 +183,7 @@ class RegexPattern(CheckURLMixin):
             )
 
     def __str__(self):
-        return self._regex
+        return str(self._regex)
 
 
 _PATH_PARAMETER_COMPONENT_RE = re.compile(
@@ -271,7 +271,7 @@ class RoutePattern(CheckURLMixin):
         return re.compile(_route_to_regex(route, self._is_endpoint)[0])
 
     def __str__(self):
-        return self._route
+        return str(self._route)
 
 
 class LocalePrefixPattern:

docs/releases/2.0.1.txt

@@ -31,3 +31,6 @@ Bugfixes
   trailing zeros in the fractional part truncated (:ticket:`28915`).
 
 * Fixed crash in the ``testserver`` command startup (:ticket:`28941`).
+
+* Fixed crash when coercing a translatable URL pattern to ``str``
+  (:ticket:`28947`).

tests/urlpatterns/test_resolvers.py

@@ -0,0 +1,15 @@
+from django.test import SimpleTestCase
+from django.urls.resolvers import RegexPattern, RoutePattern
+from django.utils.translation import gettext_lazy as _
+
+
+class RegexPatternTests(SimpleTestCase):
+
+    def test_str(self):
+        self.assertEqual(str(RegexPattern(_('^translated/$'))), '^translated/$')
+
+
+class RoutePatternTests(SimpleTestCase):
+
+    def test_str(self):
+        self.assertEqual(str(RoutePattern(_('translated/'))), 'translated/')