Based on my conversation here:

https://stackoverflow.com/questions/46441918/mongoclient-opened-before-fork-create-mongoclient/

It seems like this warning still confuses people:

UserWarning: MongoClient opened before fork. Create MongoClient with connect=False, or create client after forking. See PyMongo's documentation for details: http://api.mongodb.org/python/current/faq.html#pymongo-fork-safe>

Users might think that passing connect=False makes a client fork-safe. In fact, if they pass connect=False and use the client in a way that triggers connection, and then fork, they still risk deadlock.

The doc that the warning links to doesn't mention creating a MongoClient with connect=False.

Let's try once again to help people understand how to use PyMongo in forking programs. We have a couple options:

• Explain in the doc how to create a MongoClient with connect=False and warn users not to trigger auto-connection until after they fork
• Leave the doc as-is and remove the warning's mention of connect=False

Either way let's remove the ">" from the end of the warning message.

(Thanks for the suggestion thiago.galesi@10gen.com.)