When encoding a document in C while running in a python sub interpreter (e.g. mod_wsgi spawning sub interpreters) PyMongo would often have to reload its cache of pure python types - ObjectId, Timestamp, UUID, etc. - raising RuntimeWarning in the process. The reason this was necessary is described in the mod_wsgi documentation here: https://code.google.com/p/modwsgi/wiki/ApplicationIssues#Multiple_Python_Sub_Interpreters With workarounds documented here: http://api.mongodb.org/python/2.6.2/faq.html#does-pymongo-work-with-mod-wsgi With this commit PyMongo will no longer use cached pure python types when running in a sub interpreter. Instead it will look up pure python types as needed (primarily when decoding BSON). This eliminates the problem described in the mod_wsgi docs and eliminates the need for the Runtime warning.
Many of the pymongo modules have been moved into the bson package. Aliases for those modules have been added to the pymongo package, without deprecation warnings for now. Application developers should begin to use the bson namespace, as deprecation of moved modules will probably begin in the next release.