Allow string subclasses in truediv operations

CHANGES/871.bugfix.rst

@@ -0,0 +1 @@
+Accept string subclasses in truediv operations (``URL / segment``)

tests/test_url.py

@@ -1,3 +1,4 @@
+from enum import Enum
 from urllib.parse import SplitResult
 
 import pytest
@@ -719,6 +720,18 @@ def test_div_path_starting_from_slash_is_forbidden():
         url / "/to/others"
 
 
+class StrEnum(str, Enum):
+    spam = "ham"
+
+    def __str__(self):
+        return self.value
+
+
+def test_div_path_srting_subclass():
+    url = URL("http://example.com/path/") / StrEnum.spam
+    assert str(url) == "http://example.com/path/ham"
+
+
 def test_div_bad_type():
     url = URL("http://example.com/path/")
     with pytest.raises(TypeError):

yarl/_url.py

@@ -341,9 +341,9 @@ def __gt__(self, other):
         return self._val > other._val
 
     def __truediv__(self, name):
-        if not type(name) is str:
+        if not isinstance(name, str):
             return NotImplemented
-        return self._make_child((name,))
+        return self._make_child((str(name),))
 
     def __mod__(self, query):
         return self.update_query(query)