Fix tests for python 2.7

handel/interface.py

@@ -687,7 +687,6 @@ def get_config(*path):
 # Check version at import time
 
 if get_handel_version() < (1, 2, 19):
-    print(get_handel_version())
     warnings.warn("""\
 The current handel version is older than 1.2.19.
 This might cause bugs, especially with the FalconX.

tests/conftest.py

@@ -21,8 +21,15 @@ def interface_import():
             assert len(record) == 1
             assert "older than 1.2.19" in str(record[0].message)
 
+            # Remove mock
+            del dlopen.return_value.xiaGetVersionInfo
+            # Work around for https://bugs.python.org/issue31177
+            dlopen.return_value._mock_children.clear()
+
+            # Check dlopen
             dlopen.assert_called_once_with('handel.dll')
             assert interface.handel == dlopen.return_value
+
             yield interface