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Functional Python Programming - Second Edition
book

Functional Python Programming - Second Edition

by Steven F. Lott
April 2018
Intermediate to advanced content levelIntermediate to advanced
408 pages
10h 42m
English
Packt Publishing
Content preview from Functional Python Programming - Second Edition

Partitioning an iterator with groupby()

We can use the groupby() function to partition an iterator into smaller iterators. This works by evaluating the given key() function for each item in the given iterable. If the key value matches the previous item's key, the two items are part of the same partition. If the key does not match the previous item's key, the previous partition is ended and a new partition is started.

The output from the groupby() function is a sequence of two tuples. Each tuple has the group's key value and an iterable over the items in the group. Each group's iterator can be preserved as a tuple or processed to reduce it to some summary value. Because of the way the group iterators are created, they can't be preserved.

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Functional Python Programming - Third Edition

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Publisher Resources

ISBN: 9781788627061Supplemental Content