issue5230 writer now checks instance of loc parameter before trying to operate on it

spacy/kb.pyx

@@ -446,10 +446,10 @@ cdef class KnowledgeBase:
 
 cdef class Writer:
     def __init__(self, object loc):
-        if path.exists(loc):
-            assert not path.isdir(loc), "%s is directory." % loc
         if isinstance(loc, Path):
             loc = bytes(loc)
+        if path.exists(loc):
+            assert not path.isdir(loc), "%s is directory." % loc
         cdef bytes bytes_loc = loc.encode('utf8') if type(loc) == unicode else loc
         self._fp = fopen(<char*>bytes_loc, 'wb')
         if not self._fp:

spacy/tests/regression/test_issue5230.py

@@ -5,7 +5,7 @@ from unittest import TestCase
 import pytest
 import srsly
 from numpy import zeros
-from spacy.kb import KnowledgeBase
+from spacy.kb import KnowledgeBase, Writer
 from spacy.vectors import Vectors
 
 from spacy.language import Language
@@ -101,6 +101,19 @@ def test_to_disk_resource_warning(obj):
     assert len(warnings_list) == 0
 
 
+def test_writer_with_path_py35():
+    writer = None
+    with make_tempdir() as d:
+        path = d / "test"
+        try:
+            writer = Writer(path)
+        except Exception as e:
+            pytest.fail(str(e))
+        finally:
+            if writer:
+                writer.close()
+
+
 class TestToDiskResourceWarningUnittest(TestCase):
     def test_resource_warning(self):
         scenarios = zip(*objects_to_test)