diff --git a/dataset/freeze/format/fcsv.py b/dataset/freeze/format/fcsv.py
index 6015f43..9a18cbb 100644
--- a/dataset/freeze/format/fcsv.py
+++ b/dataset/freeze/format/fcsv.py
@@ -20,7 +20,7 @@ class CSVSerializer(Serializer):
         self.handles = {}
 
     def write(self, path, result):
-        keys = result.keys()
+        keys = list(result.keys())
         if not path in self.handles:
             fh = open(path, 'wb')
             writer = csv.writer(fh)
@@ -31,7 +31,5 @@ class CSVSerializer(Serializer):
         writer.writerow(values)
 
     def close(self):
-        for (writer, fh) in self.handles.values():
+        for writer, fh in self.handles.values():
             fh.close()
-
-
diff --git a/dataset/freeze/format/fjson.py b/dataset/freeze/format/fjson.py
index 70c49a9..47c6e63 100644
--- a/dataset/freeze/format/fjson.py
+++ b/dataset/freeze/format/fjson.py
@@ -46,4 +46,3 @@ class JSONSerializer(Serializer):
                                          data)
             fh.write(data)
             fh.close()
-
diff --git a/dataset/freeze/format/ftabson.py b/dataset/freeze/format/ftabson.py
index 6b90468..f902604 100644
--- a/dataset/freeze/format/ftabson.py
+++ b/dataset/freeze/format/ftabson.py
@@ -7,7 +7,7 @@ class TabsonSerializer(JSONSerializer):
         fields = []
         data = []
         if len(result):
-            keys = result[0].keys()
+            keys = list(result[0].keys())
             fields = [{'id': k} for k in keys]
             for row in result:
                 d = [row.get(k) for k in keys]
diff --git a/dataset/persistence/table.py b/dataset/persistence/table.py
index 9241e78..055d055 100644
--- a/dataset/persistence/table.py
+++ b/dataset/persistence/table.py
@@ -322,7 +322,7 @@ class Table(object):
         self._check_dropped()
         if not isinstance(order_by, (list, tuple)):
             order_by = [order_by]
-        order_by = filter(lambda o: o in self.table.columns, order_by)
+        order_by = [o for o in order_by if o in self.table.columns]
         order_by = [self._args_to_order_by(o) for o in order_by]
 
         args = self._args_to_clause(_filter)
@@ -358,7 +358,7 @@ class Table(object):
         """
         Returns the number of rows in the table.
         """
-        d = self.database.query(self.table.count()).next()
+        d = next(self.database.query(self.table.count()))
         return list(d.values()).pop()
 
     def distinct(self, *columns, **_filter):
diff --git a/dataset/persistence/util.py b/dataset/persistence/util.py
index 8b0580c..f41ca0b 100644
--- a/dataset/persistence/util.py
+++ b/dataset/persistence/util.py
@@ -33,7 +33,7 @@ class ResultIter(object):
         try:
             self.rp = next(self.result_proxies)
             self.count += self.rp.rowcount
-            self.keys = self.rp.keys()
+            self.keys = list(self.rp.keys())
             return True
         except StopIteration:
             return False
@@ -42,7 +42,7 @@ class ResultIter(object):
         row = self.rp.fetchone()
         if row is None:
             if self._next_rp():
-                return self.next()
+                return next(self)
             else:
                 # stop here
                 raise StopIteration