Index creation can be done for several types, but text indexes aren't mentioned. Here are the docs:

Create Index: http://api.mongodb.org/python/current/api/pymongo/collection.html#pymongo.collection.Collection.create_index

Ensure Index: http://api.mongodb.org/python/current/api/pymongo/collection.html#pymongo.collection.Collection.ensure_index

Expected documentation:
All types of index are listed, along with examples.

Actual doc:
Many types of index are listed: ascending, haystack, 2dsphere, etc., but not text indexes. Also, no examples are given.

sample text index creation example:

db.collection.ensure_index([("field": "text")])