Add itertools.batched()

[rhettinger]

This was requested on python-ideas:

 def batched(iterable, n):
 "Batch data into lists of length n. The last batch may be shorter."
 # batched('ABCDEFG', 3) --> ABC DEF G
 if n < 1:
 raise ValueError('n must be >= 1')
 it = iter(iterable)
 while (batch := list(islice(it, n))):
 yield batch

Linked PRs

• GH-98363: Have batched() return tuples #100118
• GH-98363: Shrink the physical size as well as the logical size #100138
• [3.11] GH-98363: Update batched() recipe in docs to match 3.12 #100323