diff options
Diffstat (limited to 'Doc/library/functions.rst')
| -rw-r--r-- | Doc/library/functions.rst | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index fbb3f87367..9de9db6729 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -397,6 +397,9 @@ available. They are listed here in alphabetical order. iterable if function(item)]`` if function is not ``None`` and ``[item for item in iterable if item]`` if function is ``None``. + See :func:`itertools.filterfalse` for the complementary function that returns + elements of *iterable* for which *function* returns false. + .. function:: float([x]) @@ -1077,7 +1080,8 @@ available. They are listed here in alphabetical order. default). They have no other explicit functionality; however they are used by Numerical Python and other third party extensions. Slice objects are also generated when extended indexing syntax is used. For example: - ``a[start:stop:step]`` or ``a[start:stop, i]``. + ``a[start:stop:step]`` or ``a[start:stop, i]``. See :func:`itertools.islice` + for an alternate version that returns an iterator. .. function:: sorted(iterable[, cmp[, key[, reverse]]]) @@ -1160,6 +1164,7 @@ available. They are listed here in alphabetical order. and are not allowed to be strings. The fast, correct way to concatenate a sequence of strings is by calling ``''.join(sequence)``. Note that ``sum(range(n), m)`` is equivalent to ``reduce(operator.add, range(n), m)`` + To add floating point values with extended precision, see :func:`math.fsum`\. .. versionadded:: 2.3 @@ -1329,7 +1334,9 @@ available. They are listed here in alphabetical order. :func:`xrange` is intended to be simple and fast. Implementations may impose restrictions to achieve this. The C implementation of Python restricts all arguments to native C longs ("short" Python integers), and also requires that - the number of elements fit in a native C long. + the number of elements fit in a native C long. If a larger range is needed, + an alternate version can be crafted using the :mod:`itertools` module: + ``islice(count(start, step), (stop-start+step-1)//step)``. .. function:: zip([iterable, ...]) |