Fix for issue #195

Author: HardNorth

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 ### Fixed
 - Issue [#194](https://github.com/reportportal/client-Python/issues/194): logging URL generation, by @HardNorth
+- Issue [#195](https://github.com/reportportal/client-Python/issues/195): `None` mode exception
 
 ## [5.2.4]
 ### Changed

reportportal_client/client.py

@@ -310,11 +310,13 @@ def start_launch(self,
         # We are moving 'mode' param to the constructor, next code for the
         # transition period only.
         my_kwargs = dict(kwargs)
-        mode = my_kwargs.get('mode')
-        if not mode:
-            mode = self.mode
-        else:
+        if 'mode' in my_kwargs.keys():
+            mode = my_kwargs['mode']
             del my_kwargs['mode']
+            if not mode:
+                mode = self.mode
+        else:
+            mode = self.mode
 
         request_payload = LaunchStartRequest(
             name=name,