Best Python full text search in Russian to use with Flask?

Question

Python

Good afternoon.
I'm going through the Flask Mega Tutorial by Miguel Grinberg, and the task is to implement full-text search.
Problem: I implemented Elasticsearch according to the given instructions, it searches for everything, but it works very poorly in Russian. That is, when querying "forest", it finds only the full occurrence of "forest", but does not find "forest".
Googling on the Elasticsearch topic showed that everyone uses a variety of versions (mostly ~5, while the latest is 6.3), and a significant part of the plugins, which implies Russian search, does not support versions 6+.
Actually, the question is: Is there an adequate way to force Elasticsearch 6.3 to search in Russian, or are there full-text search options with a Python implementation that are more relevant for the language?
PSChecked, just in case, English. In the base config, when requesting "second", it returns posts with a full occurrence of "second", but does not return posts with "secondary". This is how it should be (and you need to cut the config so that you can also search for the occurrence of words), or am I not understanding something? :)