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Diffstat (limited to 'Doc/library/itertools.rst')
| -rw-r--r-- | Doc/library/itertools.rst | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 6e7885e..0d20410 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -8,6 +8,11 @@ .. sectionauthor:: Raymond Hettinger <python@rcn.com> +.. testsetup:: + + from itertools import * + + This module implements a number of :term:`iterator` building blocks inspired by constructs from the Haskell and SML programming languages. Each has been recast in a form suitable for Python. @@ -333,7 +338,7 @@ loops that truncate the stream. n = len(pool) r = n if r is None else r indices = range(n) - cycles = range(n-r+1, n+1)[::-1] + cycles = range(n, n-r, -1) yield tuple(pool[i] for i in indices[:r]) while n: for i in reversed(range(r)): @@ -475,7 +480,9 @@ Examples -------- The following examples show common uses for each tool and demonstrate ways they -can be combined. :: +can be combined. + +.. doctest:: # Show a dictionary sorted and grouped by value >>> from operator import itemgetter @@ -518,7 +525,9 @@ rather than bringing the whole iterable into memory all at once. Code volume is kept small by linking the tools together in a functional style which helps eliminate temporary variables. High speed is retained by preferring "vectorized" building blocks over the use of for-loops and :term:`generator`\s -which incur interpreter overhead. :: +which incur interpreter overhead. + +.. testcode:: def take(n, seq): return list(islice(seq, n)) |