[Python-checkins] r71451 - python/branches/py3k/Doc/library/itertools.rst
raymond.hettinger
python-checkins at python.org
Fri Apr 10 21:02:41 CEST 2009
Author: raymond.hettinger
Date: Fri Apr 10 21:02:36 2009
New Revision: 71451
Log:
Add examples.
Modified:
python/branches/py3k/Doc/library/itertools.rst
Modified: python/branches/py3k/Doc/library/itertools.rst
==============================================================================
--- python/branches/py3k/Doc/library/itertools.rst (original)
+++ python/branches/py3k/Doc/library/itertools.rst Fri Apr 10 21:02:36 2009
@@ -34,30 +34,30 @@
**Infinite Iterators:**
- ================== ================= =================================================
- Iterator Arguments Results
- ================== ================= =================================================
- :func:`count` start, [step] start, start+step, start+2*step, ...
- :func:`cycle` p p0, p1, ... plast, p0, p1, ...
- :func:`repeat` elem [,n] elem, elem, elem, ... endlessly or up to n times
- ================== ================= =================================================
+================== ================= ================================================= =========================================
+Iterator Arguments Results Example
+================== ================= ================================================= =========================================
+:func:`count` start, [step] start, start+step, start+2*step, ... ``count(10) --> 10 11 12 13 14 ...``
+:func:`cycle` p p0, p1, ... plast, p0, p1, ... ``cycle('ABCD') --> A B C D A B C D ...``
+:func:`repeat` elem [,n] elem, elem, elem, ... endlessly or up to n times ``repeat(10, 3) --> 10 10 10``
+================== ================= ================================================= =========================================
**Iterators terminating on the shortest input sequence:**
- ==================== ============================ =================================================
- Iterator Arguments Results
- ==================== ============================ =================================================
- :func:`chain` p, q, ... p0, p1, ... plast, q0, q1, ...
- :func:`compress` data, selectors (d[0] if s[0]), (d[1] if s[1]), ...
- :func:`dropwhile` pred, seq seq[n], seq[n+1], starting when pred fails
- :func:`filterfalse` pred, seq elements of seq where pred(elem) is False
- :func:`groupby` iterable[, keyfunc] sub-iterators grouped by value of keyfunc(v)
- :func:`islice` seq, [start,] stop [, step] elements from seq[start:stop:step]
- :func:`starmap` func, seq func(\*seq[0]), func(\*seq[1]), ...
- :func:`tee` it, n it1, it2 , ... itn splits one iterator into n
- :func:`takewhile` pred, seq seq[0], seq[1], until pred fails
- :func:`zip_longest` p, q, ... (p[0], q[0]), (p[1], q[1]), ...
- ==================== ============================ =================================================
+==================== ============================ ================================================= =============================================================
+Iterator Arguments Results Example
+==================== ============================ ================================================= =============================================================
+:func:`chain` p, q, ... p0, p1, ... plast, q0, q1, ... ``chain('ABC', 'DEF') --> A B C D E F``
+:func:`compress` data, selectors (d[0] if s[0]), (d[1] if s[1]), ... ``compress('ABCDEF', [1,0,1,0,1,1]) --> A C E F``
+:func:`dropwhile` pred, seq seq[n], seq[n+1], starting when pred fails ``dropwhile(lambda x: x<5, [1,4,6,4,1]) --> 6 4 1``
+:func:`filterfalse` pred, seq elements of seq where pred(elem) is False ``ifilterfalse(lambda x: x%2, range(10)) --> 0 2 4 6 8``
+:func:`groupby` iterable[, keyfunc] sub-iterators grouped by value of keyfunc(v)
+:func:`islice` seq, [start,] stop [, step] elements from seq[start:stop:step] ``islice('ABCDEFG', 2, None) --> C D E F G``
+:func:`starmap` func, seq func(\*seq[0]), func(\*seq[1]), ... ``starmap(pow, [(2,5), (3,2), (10,3)]) --> 32 9 1000``
+:func:`takewhile` pred, seq seq[0], seq[1], until pred fails ``takewhile(lambda x: x<5, [1,4,6,4,1]) --> 1 4``
+:func:`tee` it, n it1, it2 , ... itn splits one iterator into n
+:func:`zip_longest` p, q, ... (p[0], q[0]), (p[1], q[1]), ... ``izip_longest('ABCD', 'xy', fillvalue='-') --> Ax By C- D-``
+==================== ============================ ================================================= =============================================================
**Combinatoric generators:**
@@ -555,43 +555,6 @@
*fillvalue* defaults to ``None``.
-.. _itertools-example:
-
-Examples
---------
-
-The following examples show common uses for each tool and demonstrate ways they
-can be combined.
-
-.. doctest::
-
- >>> # Show a dictionary sorted and grouped by value
- >>> from operator import itemgetter
- >>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3)
- >>> di = sorted(d.items(), key=itemgetter(1))
- >>> for k, g in groupby(di, key=itemgetter(1)):
- ... print(k, map(itemgetter(0), g))
- ...
- 1 ['a', 'c', 'e']
- 2 ['b', 'd', 'f']
- 3 ['g']
-
- >>> # Find runs of consecutive numbers using groupby. The key to the solution
- >>> # is differencing with a range so that consecutive numbers all appear in
- >>> # same group.
- >>> data = [ 1, 4,5,6, 10, 15,16,17,18, 22, 25,26,27,28]
- >>> for k, g in groupby(enumerate(data), lambda t:t[0]-t[1]):
- ... print(map(operator.itemgetter(1), g))
- ...
- [1]
- [4, 5, 6]
- [10]
- [15, 16, 17, 18]
- [22]
- [25, 26, 27, 28]
-
-
-
.. _itertools-recipes:
Recipes
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