Use DataFrame.attrs instead of direct attribute assignment

Fixes pandas UserWarning about creating columns via attribute names.
Uses the proper pandas API for storing metadata on DataFrames.

Author: choldgraf

github_activity/github_activity.py

@@ -461,8 +461,8 @@ def generate_activity_md(
     # add column for participants in each issue (not just original author)
     data["contributors"] = [[]] * len(data)
 
-    # Get bot users from GraphQL data
-    bot_users = getattr(data, "bot_users", set())
+    # Get bot users from GraphQL data (stored in DataFrame attrs)
+    bot_users = data.attrs.get("bot_users", set())
 
     def ignored_user(username):
         if username in bot_users:

github_activity/graphql.py

@@ -274,8 +274,8 @@ def is_bot(user_dict):
 
         # Create a dataframe of the issues and/or PRs
         self.data = pd.DataFrame(self.issues_and_or_prs)
-        # Attach bot users set to dataframe for use in github_activity.py
-        self.data.bot_users = bot_users
+        # Store bot users in DataFrame metadata (attrs dict)
+        self.data.attrs["bot_users"] = bot_users
 
         # Add some extra fields
         def get_login(user):