from multi_rake import Rake
text_en = (
'Compatibility of systems of linear constraints over the set of '
'natural numbers. Criteria of compatibility of a system of linear '
'Diophantine equations, strict inequations, and nonstrict inequations '
'are considered. Upper bounds for components of a minimal set of '
'solutions and algorithms of construction of minimal generating sets '
'of solutions for all types of systems are given. These criteria and '
'the corresponding algorithms for constructing a minimal supporting '
'set of solutions can be used in solving all the considered types of '
'systems and systems of mixed types.'
)
rake = Rake()
keywords = rake.apply(text_en)
print(keywords[:10])
# ('minimal generating sets', 8.666666666666666),
# ('linear diophantine equations', 8.5),
# ('minimal supporting set', 7.666666666666666),
# ('minimal set', 4.666666666666666),
# ('linear constraints', 4.5),
# ('natural numbers', 4.0),
# ('strict inequations', 4.0),
# ('nonstrict inequations', 4.0),
# ('upper bounds', 4.0),
# ('mixed types', 3.666666666666667)