From 367af52ecc424d598dd0d1c1886800755f10dd4e Mon Sep 17 00:00:00 2001
From: Mikhail Astafev <astafan8@gmail.com>
Date: Thu, 5 Aug 2021 17:32:47 +0200
Subject: [PATCH] Add encode_as_NAType to encode pandas NAType to json

---
 packages/python/plotly/_plotly_utils/utils.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/packages/python/plotly/_plotly_utils/utils.py b/packages/python/plotly/_plotly_utils/utils.py
index 9254b7f23d2..d3db9c9663f 100644
--- a/packages/python/plotly/_plotly_utils/utils.py
+++ b/packages/python/plotly/_plotly_utils/utils.py
@@ -127,6 +127,7 @@ def default(self, obj):
             self.encode_as_list,  # because some values have `tolist` do last.
             self.encode_as_decimal,
             self.encode_as_pil,
+            self.encode_as_NAType,
         )
         for encoding_method in encoding_methods:
             try:
@@ -135,6 +136,14 @@ def default(self, obj):
                 pass
         return _json.JSONEncoder.default(self, obj)
 
+    @staticmethod
+    def encode_as_NAType(obj):
+        from pandas._libs.missing import NAType
+        if isinstance(obj, NAType):
+            return None
+        else:
+            raise NotEncodable
+
     @staticmethod
     def encode_as_plotly(obj):
         """Attempt to use a builtin `to_plotly_json` method."""