diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst index 2f7785e81db..d6d7ebbec9d 100644 --- a/Doc/library/collections.rst +++ b/Doc/library/collections.rst @@ -251,14 +251,12 @@ Common patterns for working with :class:`Counter` objects:: c.most_common()[:-n:-1] # n least common elements c += Counter() # remove zero and negative counts -Several multiset mathematical operations are provided for combining -:class:`Counter` objects. Multisets are counters with the restriction -that all counts are at least one. They are like regular sets but are -allowed to contain repeated elements. Addition and subtraction combine -counters by adding or subtracting the counts of corresponding elements. -Intersection and union return the minimum and maximum of corresponding -counts. Each operation can accept inputs with signed counts, -but the output excludes results with counts less than one. +Several mathematical operations are provided for combining :class:`Counter` +objects to produce multisets (counters that have counts greater than zero). +Addition and subtraction combine counters by adding or subtracting the counts +of corresponding elements. Intersection and union return the minimum and +maximum of corresponding counts. Each operation can accept inputs with signed +counts, but the output will exclude results with counts of zero or less. >>> c = Counter(a=3, b=1) >>> d = Counter(a=1, b=2)