Update exceptions.mustache

Author: ddl-rliu

modules/openapi-generator/src/main/resources/python/exceptions.mustache

@@ -160,8 +160,11 @@ class ApiException(OpenApiException):
             error_message += "HTTP response headers: {0}\n".format(
                 self.headers)
 
-        if self.data or self.body:
-            error_message += "HTTP response body: {0}\n".format(self.data or self.body)
+        if self.body:
+            error_message += "HTTP response body: {0}\n".format(self.body)
+
+        if self.data:
+            error_message += "HTTP response data: {0}\n".format(self.data)
 
         return error_message