mirror of
https://github.com/kennethreitz/dive-into-python3.git
synced 2026-06-05 23:10:17 +00:00
Mark Pilgrim
105 lines
3.6 KiB
HTML
105 lines
3.6 KiB
HTML
<!DOCTYPE html>
|
|
<head>
|
|
<meta charset=utf-8>
|
|
<title>Advanced Classes - Dive into Python 3</title>
|
|
<!--[if IE]><script src=html5.js></script><![endif]-->
|
|
<link rel=stylesheet href=dip3.css>
|
|
<style>
|
|
body{counter-reset:h1 11}
|
|
</style>
|
|
<link rel=stylesheet media='only screen and (max-device-width: 480px)' href=mobile.css>
|
|
</head>
|
|
<form action=http://www.google.com/cse><div><input type=hidden name=cx value=014021643941856155761:l5eihuescdw><input type=hidden name=ie value=UTF-8> <input name=q size=25> <input type=submit name=sa value=Search></div></form>
|
|
<p>You are here: <a href=index.html>Home</a> <span>‣</span> <a href=table-of-contents.html#advanced-classes>Dive Into Python 3</a> <span>‣</span>
|
|
<p id=level>Difficulty level: <span title=advanced>♦♦♦♦♢</span>
|
|
<h1>Advanced Classes</h1>
|
|
<blockquote class=q>
|
|
<p><span>❝</span> FIXME <span>❞</span><br>— FIXME
|
|
</blockquote>
|
|
<p id=toc>
|
|
<h2 id=divingin>Diving In</h2>
|
|
<p class=f>FIXME
|
|
|
|
<h2 id=ordereddict>Ordered Dictionary: Not An Oxymoron</h2>
|
|
|
|
<p>[FIXME here's why ordered dicts are useful: http://www.gossamer-threads.com/lists/python/dev/656556 ]
|
|
|
|
<p class=d>[<a href=examples/ordereddict.py>download <code>ordereddict.py</code></a>]
|
|
<pre><code>import collections
|
|
import itertools
|
|
|
|
class OrderedDict(dict, collections.MutableMapping):
|
|
|
|
def __init__(self, *args, **kwds):
|
|
if len(args) > 1:
|
|
raise TypeError('expected at most 1 arguments')
|
|
if not hasattr(self, '_keys'):
|
|
self._keys = []
|
|
self.update(*args, **kwds)
|
|
|
|
def clear(self):
|
|
del self._keys[:]
|
|
dict.clear(self)
|
|
|
|
def __setitem__(self, key, value):
|
|
if key not in self:
|
|
self._keys.append(key)
|
|
dict.__setitem__(self, key, value)
|
|
|
|
def __delitem__(self, key):
|
|
dict.__delitem__(self, key)
|
|
self._keys.remove(key)
|
|
|
|
def __iter__(self):
|
|
return iter(self._keys)
|
|
|
|
def __reversed__(self):
|
|
return reversed(self._keys)
|
|
|
|
def popitem(self):
|
|
if not self:
|
|
raise KeyError('dictionary is empty')
|
|
key = self._keys.pop()
|
|
value = dict.pop(self, key)
|
|
return key, value
|
|
|
|
def __reduce__(self):
|
|
items = [[k, self[k]] for k in self]
|
|
inst_dict = vars(self).copy()
|
|
inst_dict.pop('_keys', None)
|
|
return (self.__class__, (items,), inst_dict)
|
|
|
|
setdefault = MutableMapping.setdefault
|
|
update = MutableMapping.update
|
|
pop = MutableMapping.pop
|
|
keys = MutableMapping.keys
|
|
values = MutableMapping.values
|
|
items = MutableMapping.items
|
|
|
|
def __repr__(self):
|
|
if not self:
|
|
return '%s()' % (self.__class__.__name__,)
|
|
return '%s(%r)' % (self.__class__.__name__, list(self.items()))
|
|
|
|
def copy(self):
|
|
return self.__class__(self)
|
|
|
|
@classmethod
|
|
def fromkeys(cls, iterable, value=None):
|
|
d = cls()
|
|
for key in iterable:
|
|
d[key] = value
|
|
return d
|
|
|
|
def __eq__(self, other):
|
|
if isinstance(other, OrderedDict):
|
|
return all(p==q for p, q in itertools.zip_longest(self.items(), other.items()))
|
|
return dict.__eq__(self, other)</code></pre>
|
|
|
|
<h2 id=implementing-fractions>Implementing Fractions</h2>
|
|
|
|
<p class=nav><a rel=prev class=todo><span>☜</span></a> <a rel=next class=todo><span>☞</span></a>
|
|
<p class=c>© 2001–9 <a href=about.html>Mark Pilgrim</a>
|
|
<script src=jquery.js></script>
|
|
<script src=dip3.js></script>
|