python3-stemmer binary package in Ubuntu Focal amd64

 PyStemmer provides access to efficient algorithms for calculating a "stemmed"
 form of a word. This is a form with most of the common morphological endings
 removed; hopefully representing a common linguistic base form. This is most
 useful in building search engines and information retrieval software; for
 example, a search with stemming enabled should be able to find a document
 containing "cycling" given the query "cycles".
 .
 PyStemmer provides algorithms for several (mainly European) languages, by
 wrapping the libstemmer library from the Snowball project in a Python 3
 module.
 .
 It also provides access to the classic Porter stemming algorithm for English:
 although this has been superseded by an improved algorithm, the original
 algorithm may be of interest to information retrieval researchers wishing to
 reproduce results of earlier experiments.

Source package