diff options
Diffstat (limited to 'Doc/library/itertools.rst')
| -rw-r--r-- | Doc/library/itertools.rst | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 1b5ff81..80fe34d 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -210,7 +210,10 @@ loops that truncate the stream. iterables = [iter(it) for it in iterables) while True: args = [next(it) for it in iterables] - yield function(*args) + if function is None: + yield tuple(args) + else: + yield function(*args) .. function:: islice(iterable, [start,] stop [, step]) @@ -252,12 +255,11 @@ loops that truncate the stream. When no iterables are specified, return a zero length iterator. - Note, the left-to-right evaluation order of the iterables is guaranteed. This - makes possible an idiom for clustering a data series into n-length groups using - ``izip(*[iter(s)]*n)``. For data that doesn't fit n-length groups exactly, the - last tuple can be pre-padded with fill values using ``izip(*[chain(s, - [None]*(n-1))]*n)``. + The left-to-right evaluation order of the iterables is guaranteed. This + makes possible an idiom for clustering a data series into n-length groups + using ``izip(*[iter(s)]*n)``. +<<<<<<< .working Note, when :func:`izip` is used with unequal length inputs, subsequent iteration over the longer iterables cannot reliably be continued after :func:`izip` terminates. Potentially, up to one entry will be missing from @@ -268,6 +270,11 @@ loops that truncate the stream. the iterator for retrieval with ``next(it)``). In general, :func:`izip` should only be used with unequal length inputs when you don't care about trailing, unmatched values from the longer iterables. +======= + :func:`izip` should only be used with unequal length inputs when you don't + care about trailing, unmatched values from the longer iterables. If those + values are important, use :func:`izip_longest` instead. +>>>>>>> .merge-right.r60208 .. function:: izip_longest(*iterables[, fillvalue]) |