diff --git a/src/common/src/tstring.c b/src/common/src/tmessage.c
similarity index 100%
rename from src/common/src/tstring.c
rename to src/common/src/tmessage.c
diff --git a/src/connector/python/linux/python2/taos/cinterface.py b/src/connector/python/linux/python2/taos/cinterface.py
index 505619436c..d9460efb21 100644
--- a/src/connector/python/linux/python2/taos/cinterface.py
+++ b/src/connector/python/linux/python2/taos/cinterface.py
@@ -316,6 +316,9 @@ class CTaosInterface(object):
         blocks = [None] * len(fields)
         for i in range(len(fields)):
             data = ctypes.cast(pblock, ctypes.POINTER(ctypes.c_void_p))[i]
+            if data == None:
+                blocks[i] = [None] * num_of_rows
+                continue
 
             if fields[i]['type'] not in _CONVERT_FUNC:
                 raise DatabaseError("Invalid data type returned from database")
diff --git a/src/connector/python/linux/python3/taos/cinterface.py b/src/connector/python/linux/python3/taos/cinterface.py
index 7fcedc9fe9..77001609b6 100644
--- a/src/connector/python/linux/python3/taos/cinterface.py
+++ b/src/connector/python/linux/python3/taos/cinterface.py
@@ -316,6 +316,9 @@ class CTaosInterface(object):
         blocks = [None] * len(fields)
         for i in range(len(fields)):
             data = ctypes.cast(pblock, ctypes.POINTER(ctypes.c_void_p))[i]
+            if data == None:
+                blocks[i] = [None] * num_of_rows
+                continue
 
             if fields[i]['type'] not in _CONVERT_FUNC:
                 raise DatabaseError("Invalid data type returned from database")
diff --git a/src/connector/python/windows/python2/taos/cinterface.py b/src/connector/python/windows/python2/taos/cinterface.py
index f8cdfcc51e..a18d372db2 100644
--- a/src/connector/python/windows/python2/taos/cinterface.py
+++ b/src/connector/python/windows/python2/taos/cinterface.py
@@ -316,6 +316,9 @@ class CTaosInterface(object):
         blocks = [None] * len(fields)
         for i in range(len(fields)):
             data = ctypes.cast(pblock, ctypes.POINTER(ctypes.c_void_p))[i]
+            if data == None:
+                blocks[i] = [None] * num_of_rows
+                continue
 
             if fields[i]['type'] not in _CONVERT_FUNC:
                 raise DatabaseError("Invalid data type returned from database")
diff --git a/src/connector/python/windows/python3/taos/cinterface.py b/src/connector/python/windows/python3/taos/cinterface.py
index b4b44e199c..cbcf2d884e 100644
--- a/src/connector/python/windows/python3/taos/cinterface.py
+++ b/src/connector/python/windows/python3/taos/cinterface.py
@@ -316,6 +316,9 @@ class CTaosInterface(object):
         blocks = [None] * len(fields)
         for i in range(len(fields)):
             data = ctypes.cast(pblock, ctypes.POINTER(ctypes.c_void_p))[i]
+            if data == None:
+                blocks[i] = [None] * num_of_rows
+                continue
 
             if fields[i]['type'] not in _CONVERT_FUNC:
                 raise DatabaseError("Invalid data type returned from database")