preemptively import orjson

without this, in mode="jupyterlab" we see (sometimes):
  AttributeError: partially initialized module 'orjson' has no attribute
  'OPT_SORT_KEYS' (most likely due to a circular import)

Author: alexcjohnson

jupyter_dash/jupyter_app.py

@@ -287,6 +287,14 @@ def run_server(
             inline_exceptions=inline_exceptions,
         )
 
+        # prevent partial import of orjson when it's installed and mode=jupyterlab
+        # TODO: why do we need this? Why only in this mode? Importing here in
+        # all modes anyway, in case there's a way it can pop up in another mode
+        try:
+            import orjson
+        except ImportError:
+            pass
+
         @retry(
             stop_max_attempt_number=15,
             wait_exponential_multiplier=100,