fixed tests.

changed miniuri/miniuri.py
changed test_miniuri.py

miniuri/miniuri.py

@@ -33,7 +33,7 @@ class Uri( object ):
         """parse and set all uri attributes"""
         self.scheme = self.username = self.password = None
         self.hostname = self.port = self.path = None
-        self.filename = self.extension = self.query = self.fragment = None 
+        self.filename = self.query = self.fragment = None 
 
         if '://' in uri: # attempt to parse scheme
             self.scheme, uri = uri.split( '://' )
@@ -99,21 +99,24 @@ class Uri( object ):
             self.filename = new_path.split('/')[-1]
             self._path = new_path.rstrip(self.filename)
         else:
+            self.filename = None
             self._path = None
-            self._filename = None
-            self._extension = None
 
     @property
     def filename(self):
         """return filename"""
         if self._filename: 
             if self.extension:
-                return self._filename + '.' + self.extension
+                return '{}.{}'.format(self._filename, self.extension)
             return self._filename
+        return ''
 
     @filename.setter
     def filename(self, new_filename):
+        self.extension = ''
         if new_filename:
-            self.extension = new_filename.split('.')[-1] if '.' in new_filename else None
             self._filename = new_filename.split('.')[0]
-
+            if '.' in new_filename:
+                self.extension = new_filename.split('.')[-1]
+        else:
+            self._filename = None

test_miniuri.py

@@ -58,7 +58,7 @@ class TestMiniUri(TestCase):
         self.assertEqual(self.u.port, '81')
         self.assertEqual(self.u.path, '')
         self.assertEqual(self.u.filename, '')
-        self.assertEqual(self.u.extention, '')
+        self.assertEqual(self.u.extension, '')
 
     def test_uri_filename_only_path(self):
         self.u = Uri('https://fox:pass@www.foxhop.net:81/filename.jpg?p=2#5')