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authorTerry Reedy <tjreedy@udel.edu>2011-01-11 23:05:50 (GMT)
committerTerry Reedy <tjreedy@udel.edu>2011-01-11 23:05:50 (GMT)
commitfdf29254521cd49c06312195d734c2061706fafb (patch)
tree3a4c861e4702f7588efae5672de2cd241e679656 /Doc/howto/sorting.rst
parent524359f9f7cf2cbd168bcc8464d05684b6774181 (diff)
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Issue #10225: Correct interactive Doc/howto/sorting.rst examples so doctest runs.
Based on part of A. Belopolsky's patch.
Diffstat (limited to 'Doc/howto/sorting.rst')
-rw-r--r--Doc/howto/sorting.rst79
1 files changed, 39 insertions, 40 deletions
diff --git a/Doc/howto/sorting.rst b/Doc/howto/sorting.rst
index 134c9ce..af1149d 100644
--- a/Doc/howto/sorting.rst
+++ b/Doc/howto/sorting.rst
@@ -4,7 +4,6 @@ Sorting HOW TO
**************
:Author: Andrew Dalke and Raymond Hettinger
-:Release: 0.1
Python lists have a built-in :meth:`list.sort` method that modifies the list
@@ -18,7 +17,7 @@ Sorting Basics
==============
A simple ascending sort is very easy: just call the :func:`sorted` function. It
-returns a new sorted list::
+returns a new sorted list:
>>> sorted([5, 2, 3, 1, 4])
[1, 2, 3, 4, 5]
@@ -58,28 +57,28 @@ A common pattern is to sort complex objects using some of the object's indices
as keys. For example:
>>> student_tuples = [
- ('john', 'A', 15),
- ('jane', 'B', 12),
- ('dave', 'B', 10),
- ]
+ ... ('john', 'A', 15),
+ ... ('jane', 'B', 12),
+ ... ('dave', 'B', 10),
+ ... ]
>>> sorted(student_tuples, key=lambda student: student[2]) # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
The same technique works for objects with named attributes. For example:
>>> class Student:
- def __init__(self, name, grade, age):
- self.name = name
- self.grade = grade
- self.age = age
- def __repr__(self):
- return repr((self.name, self.grade, self.age))
+ ... def __init__(self, name, grade, age):
+ ... self.name = name
+ ... self.grade = grade
+ ... self.age = age
+ ... def __repr__(self):
+ ... return repr((self.name, self.grade, self.age))
>>> student_objects = [
- Student('john', 'A', 15),
- Student('jane', 'B', 12),
- Student('dave', 'B', 10),
- ]
+ ... Student('john', 'A', 15),
+ ... Student('jane', 'B', 12),
+ ... Student('dave', 'B', 10),
+ ... ]
>>> sorted(student_objects, key=lambda student: student.age) # sort by age
[('dave', 'B', 10), ('jane', 'B', 12), ('john', 'A', 15)]
@@ -208,39 +207,39 @@ return a negative value for less-than, return zero if they are equal, or return
a positive value for greater-than. For example, we can do:
>>> def numeric_compare(x, y):
- return x - y
- >>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare)
+ ... return x - y
+ >>> sorted([5, 2, 4, 1, 3], cmp=numeric_compare) # doctest: +SKIP
[1, 2, 3, 4, 5]
Or you can reverse the order of comparison with:
>>> def reverse_numeric(x, y):
- return y - x
- >>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric)
+ ... return y - x
+ >>> sorted([5, 2, 4, 1, 3], cmp=reverse_numeric) # doctest: +SKIP
[5, 4, 3, 2, 1]
When porting code from Python 2.x to 3.x, the situation can arise when you have
the user supplying a comparison function and you need to convert that to a key
-function. The following wrapper makes that easy to do::
-
- def cmp_to_key(mycmp):
- 'Convert a cmp= function into a key= function'
- class K(object):
- def __init__(self, obj, *args):
- self.obj = obj
- def __lt__(self, other):
- return mycmp(self.obj, other.obj) < 0
- def __gt__(self, other):
- return mycmp(self.obj, other.obj) > 0
- def __eq__(self, other):
- return mycmp(self.obj, other.obj) == 0
- def __le__(self, other):
- return mycmp(self.obj, other.obj) <= 0
- def __ge__(self, other):
- return mycmp(self.obj, other.obj) >= 0
- def __ne__(self, other):
- return mycmp(self.obj, other.obj) != 0
- return K
+function. The following wrapper makes that easy to do:
+
+ >>> def cmp_to_key(mycmp):
+ ... 'Convert a cmp= function into a key= function'
+ ... class K(object):
+ ... def __init__(self, obj, *args):
+ ... self.obj = obj
+ ... def __lt__(self, other):
+ ... return mycmp(self.obj, other.obj) < 0
+ ... def __gt__(self, other):
+ ... return mycmp(self.obj, other.obj) > 0
+ ... def __eq__(self, other):
+ ... return mycmp(self.obj, other.obj) == 0
+ ... def __le__(self, other):
+ ... return mycmp(self.obj, other.obj) <= 0
+ ... def __ge__(self, other):
+ ... return mycmp(self.obj, other.obj) >= 0
+ ... def __ne__(self, other):
+ ... return mycmp(self.obj, other.obj) != 0
+ ... return K
To convert to a key function, just wrap the old comparison function: