diff --git a/tempsdb/database.pxd b/tempsdb/database.pxd
index 9d7fbb8be64d6ff39e095c2372fe07bcf01f685a..ddbabf8019970d97bf3dd86b70c91bcb990fed85 100644
--- a/tempsdb/database.pxd
+++ b/tempsdb/database.pxd
@@ -15,7 +15,7 @@ cdef class Database:
     cpdef TimeSeries get_series(self, str name,
                                 bint use_descriptor_based_access=*)
     cpdef VarlenSeries get_varlen_series(self, str name)
-    cpdef int register_memory_pressure_manager(self, object mpm) except -1
+    cpdef int register_memory_pressure_manager( self, object mpm) except -1
     cpdef TimeSeries create_series(self, str name, int block_size,
                                    unsigned long entries_per_chunk,
                                    int page_size=*,
diff --git a/tempsdb/varlen.pyx b/tempsdb/varlen.pyx
index 36c9f1d2504fba9e831b8b1c8fd39e1b49f0973b..e79abe2e34b4c3a78f50d10ca67499c2fd054b3f 100644
--- a/tempsdb/varlen.pyx
+++ b/tempsdb/varlen.pyx
@@ -433,6 +433,12 @@ cdef class VarlenSeries:
                                        bint direct_bytes=False):
         """
         Return an iterator with the data
+        
+        :param start: timestamp to start iterating
+        :param stop: timestamp to stop iterating at
+        :param direct_bytes: whether to return a tuple of (int, bytes) instead of 
+            (int, :class:`~tempsdb.varlen.VarlenEntry`)
+        :return: a :class:`~tempsdb.varlen.VarlenIterator` instance
         """
         return VarlenIterator(self, start, stop, direct_bytes=direct_bytes)
 
diff --git a/tests/test_db.py b/tests/test_chunks.py
similarity index 59%
rename from tests/test_db.py
rename to tests/test_chunks.py
index 91716d13aff99da11b48d2fc3f184eecaf63c714..9e5b4b3e55475c68d97a9d228ae63d97b9b6dd6b 100644
--- a/tests/test_db.py
+++ b/tests/test_chunks.py
@@ -3,68 +3,6 @@ import unittest
 
 
 class TestDB(unittest.TestCase):
-    def test_write_series(self):
-        from tempsdb.series import create_series
-        series = create_series('test3', 'test3', 10, 4096)
-        for i in range(8000):
-            series.append(i, b'\x00'*10)
-
-        self.assertEqual(series.get_current_value(), (i, b'\x00'*10))
-
-        with series.iterate_range(i, i) as it:
-            lst = list(it)
-            self.assertEqual(len(lst), 1)
-            self.assertEqual(lst[0][0], i)
-
-        series.trim(4100)
-
-        self.assertEqual(len(os.listdir('test3')), 2)
-        series.close()
-
-    def test_create_series(self):
-        from tempsdb.series import create_series
-
-        series = create_series('test', 'test', 1, 10)
-        start, ts = 127, 100
-        for i in range(20):
-            series.append(ts, bytes(bytearray([start])))
-            start -= 1
-            ts += 100
-
-        self.do_verify_series(series, 0, 2000)
-        self.do_verify_series(series, 500, 2000)
-        self.do_verify_series(series, 1000, 2000)
-        self.do_verify_series(series, 1500, 2000)
-        self.do_verify_series(series, 0, 500)
-        self.do_verify_series(series, 0, 1200)
-        self.do_verify_series(series, 0, 1800)
-        series.close()
-
-    def test_create_series_gzip(self):
-        from tempsdb.series import create_series
-
-        series = create_series('test.gz', 'test.gz', 1, 10, gzip_level=6)
-        start, ts = 127, 100
-        for i in range(20):
-            series.append(ts, bytes(bytearray([start])))
-            start -= 1
-            ts += 100
-
-        self.do_verify_series(series, 0, 2000)
-        self.do_verify_series(series, 500, 2000)
-        self.do_verify_series(series, 1000, 2000)
-        self.do_verify_series(series, 1500, 2000)
-        self.do_verify_series(series, 0, 500)
-        self.do_verify_series(series, 0, 1200)
-        self.do_verify_series(series, 0, 1800)
-        series.close()
-
-    def do_verify_series(self, series, start, stop):
-        it = series.iterate_range(start, stop)
-        items = list(it)
-        it.close()
-        self.assertGreaterEqual(items[0][0], start)
-        self.assertLessEqual(items[-1][0], stop)
 
     def test_chunk_alternative(self):
         from tempsdb.chunks.normal import NormalChunk
diff --git a/tests/test_series.py b/tests/test_series.py
new file mode 100644
index 0000000000000000000000000000000000000000..66f03136c0e9fe27fc1dede69ca6cafe495d9815
--- /dev/null
+++ b/tests/test_series.py
@@ -0,0 +1,67 @@
+import os
+import unittest
+
+
+class TestSeries(unittest.TestCase):
+    def test_write_series(self):
+        from tempsdb.series import create_series
+        series = create_series('test3', 'test3', 10, 4096)
+        for i in range(8000):
+            series.append(i, b'\x00'*10)
+
+        self.assertEqual(series.get_current_value(), (i, b'\x00'*10))
+
+        with series.iterate_range(i, i) as it:
+            lst = list(it)
+            self.assertEqual(len(lst), 1)
+            self.assertEqual(lst[0][0], i)
+
+        series.trim(4100)
+
+        self.assertEqual(len(os.listdir('test3')), 2)
+        series.close()
+
+    def test_create_series(self):
+        from tempsdb.series import create_series
+
+        series = create_series('test', 'test', 1, 10)
+        start, ts = 127, 100
+        for i in range(20):
+            series.append(ts, bytes(bytearray([start])))
+            start -= 1
+            ts += 100
+
+        self.do_verify_series(series, 0, 2000)
+        self.do_verify_series(series, 500, 2000)
+        self.do_verify_series(series, 1000, 2000)
+        self.do_verify_series(series, 1500, 2000)
+        self.do_verify_series(series, 0, 500)
+        self.do_verify_series(series, 0, 1200)
+        self.do_verify_series(series, 0, 1800)
+        series.close()
+
+    def test_create_series_gzip(self):
+        from tempsdb.series import create_series
+
+        series = create_series('test.gz', 'test.gz', 1, 10, gzip_level=6)
+        start, ts = 127, 100
+        for i in range(20):
+            series.append(ts, bytes(bytearray([start])))
+            start -= 1
+            ts += 100
+
+        self.do_verify_series(series, 0, 2000)
+        self.do_verify_series(series, 500, 2000)
+        self.do_verify_series(series, 1000, 2000)
+        self.do_verify_series(series, 1500, 2000)
+        self.do_verify_series(series, 0, 500)
+        self.do_verify_series(series, 0, 1200)
+        self.do_verify_series(series, 0, 1800)
+        series.close()
+
+    def do_verify_series(self, series, start, stop):
+        it = series.iterate_range(start, stop)
+        items = list(it)
+        it.close()
+        self.assertGreaterEqual(items[0][0], start)
+        self.assertLessEqual(items[-1][0], stop)