http://code.activestate.com/recipes/langs/python/top/2013-01-17T09:28:24-08:00ActiveState Code Recipes2010-11-16T08:36:38-08:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/277940-decorator-for-bindingconstants-at-compile-time/

<p style="color: grey"> Python recipe 277940 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/programs/">programs</a>). Revision 9. </p> <p>Decorator for automatic code optimization. If a global is known at compile time, replace it with a constant. Fold tuples of constants into a single constant. Fold constant attribute lookups into a single constant.</p>

2005-02-17T11:12:04-08:00Ferdinand Jamitzkyhttp://code.activestate.com/recipes/users/98863/http://code.activestate.com/recipes/384122-infix-operators/

<p style="color: grey"> Python recipe 384122 by <a href="/recipes/users/98863/">Ferdinand Jamitzky</a> (<a href="/recipes/tags/oop/">oop</a>). Revision 3. </p> <p>Python has the wonderful "in" operator and it would be nice to have additional infix operator like this. This recipe shows how (almost) arbitrary infix operators can be defined.</p>

2004-12-03T09:13:43-08:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/355045-spreadsheet/

<p style="color: grey"> Python recipe 355045 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/programs/">programs</a>). Revision 2. </p> <p>Use eval() to drive spreadsheet style logic. The sleeper feature of Py2.4 is the ability to use any object with a mapping interface as the locals argument to eval().</p>

2009-05-26T22:44:39-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/500261-named-tuples/

<p style="color: grey"> Python recipe 500261 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/shortcuts/">shortcuts</a>). Revision 15. </p> <p>Fast, lightweight attribute-style access to tuples.</p>

2005-01-31T22:06:30-08:00Maxim Krikunhttp://code.activestate.com/recipes/users/1085177/http://code.activestate.com/recipes/365013-linear-equations-solver-in-3-lines/

<p style="color: grey"> Python recipe 365013 by <a href="/recipes/users/1085177/">Maxim Krikun</a> (<a href="/recipes/tags/programs/">programs</a>). Revision 2. </p> <p>Just a little bit of hack: a linear equations solver using eval and built-in complex numbers:</p> <pre class="prettyprint"><code>&gt;&gt;&gt; solve("x - 2*x + 5*x - 46*(235-24) = x + 2") 3236.0 </code></pre>

2001-08-27T08:05:21-07:00Alex Martellihttp://code.activestate.com/recipes/users/97991/http://code.activestate.com/recipes/66531-singleton-we-dont-need-no-stinkin-singleton-the-bo/

<p style="color: grey"> Python recipe 66531 by <a href="/recipes/users/97991/">Alex Martelli</a> (<a href="/recipes/tags/oop/">oop</a>). Revision 2. </p> <p>The Singleton design pattern (DP) has a catchy name, but the wrong focus -- on identity rather than on state. The Borg design pattern has all instances share state instead, and Python makes it, literally, a snap.</p>

2006-01-29T18:40:36-08:00darrin massenahttp://code.activestate.com/recipes/users/1987292/http://code.activestate.com/recipes/473810-send-an-html-email-with-embedded-image-and-plain-t/

<p style="color: grey"> Python recipe 473810 by <a href="/recipes/users/1987292/">darrin massena</a> (<a href="/recipes/tags/network/">network</a>). </p> <p>HTML is the method of choice for those wishing to send emails with rich text, layout and graphics. Often it is desirable to embed the graphics within the message so recipients can display the message directly, without further downloads.</p> <p>Some mail agents don't support HTML or their users prefer to receive plain text messages. Senders of HTML messages should include a plain text message as an alternate for these users.</p> <p>This recipe sends a short HTML message with a single embedded image and an alternate plain text message.</p>

2005-10-03T16:49:09-07:00Chad J. Schroederhttp://code.activestate.com/recipes/users/1760491/http://code.activestate.com/recipes/278731-creating-a-daemon-the-python-way/

<p style="color: grey"> Python recipe 278731 by <a href="/recipes/users/1760491/">Chad J. Schroeder</a> (<a href="/recipes/tags/threads/">threads</a>). Revision 6. </p> <p>The Python way to detach a process from the controlling terminal and run it in the background as a daemon.</p>

2004-02-12T07:05:02-08:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/259173-groupby/

<p style="color: grey"> Python recipe 259173 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/algorithms/">algorithms</a>). Revision 5. </p> <p>Guido inspired SQL-like GROUPBY class that also encapsulates the logic in a Unix-like "sort | uniq".</p>

2005-04-26T10:51:04-07:00Brian Beckhttp://code.activestate.com/recipes/users/2425329/http://code.activestate.com/recipes/410692-readable-switch-construction-without-lambdas-or-di/

<p style="color: grey"> Python recipe 410692 by <a href="/recipes/users/2425329/">Brian Beck</a> (<a href="/recipes/tags/extending/">extending</a>). Revision 8. </p> <p>Python's lack of a 'switch' statement has garnered much discussion and even a PEP. The most popular substitute uses dictionaries to map cases to functions, which requires lots of defs or lambdas. While the approach shown here may be O(n) for cases, it aims to duplicate C's original 'switch' functionality and structure with reasonable accuracy.</p>

2011-06-04T17:44:21-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/577684-bloom-filter/

<p style="color: grey"> Python recipe 577684 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/big_table/">big_table</a>, <a href="/recipes/tags/bloom_filter/">bloom_filter</a>, <a href="/recipes/tags/sets/">sets</a>, <a href="/recipes/tags/spelling_checker/">spelling_checker</a>, <a href="/recipes/tags/spell_checker/">spell_checker</a>). Revision 18. </p> <p>Space efficient, probabilistic set membership tester. Has no False Negatives but allows a rare False Positive.</p>

2013-01-17T09:28:24-08:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/578375-proof-of-concept-for-a-more-space-efficient-faster/

<p style="color: grey"> Python recipe 578375 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/compact/">compact</a>, <a href="/recipes/tags/dictionary/">dictionary</a>). Revision 20. </p> <p>Save space and improve iteration speed by moving the hash/key/value entries to a densely packed array keeping only a sparse array of indices. This eliminates wasted space without requiring any algorithmic changes.</p>

2005-05-09T16:53:44-07:00Zoran Isailovskihttp://code.activestate.com/recipes/users/2400454/http://code.activestate.com/recipes/413486-first-class-enums-in-python/

<p style="color: grey"> Python recipe 413486 by <a href="/recipes/users/2400454/">Zoran Isailovski</a> (<a href="/recipes/tags/programs/">programs</a>). Revision 7. </p> <p>True immutable symbolic enumeration with qualified value access.</p>

2007-03-10T11:26:16-08:00Zoran Isailovskihttp://code.activestate.com/recipes/users/2400454/http://code.activestate.com/recipes/413268-dependency-injection-the-python-way/

<p style="color: grey"> Python recipe 413268 by <a href="/recipes/users/2400454/">Zoran Isailovski</a> (<a href="/recipes/tags/oop/">oop</a>). Revision 9. </p> <p>Sample Pythonic Inversion-of-Control Pseudo-Container.</p>

2011-05-15T16:46:55-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/577676-dirt-simple-mapreduce/

<p style="color: grey"> Python recipe 577676 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/analysis/">analysis</a>, <a href="/recipes/tags/crosstab/">crosstab</a>, <a href="/recipes/tags/functional/">functional</a>, <a href="/recipes/tags/map_reduce/">map_reduce</a>, <a href="/recipes/tags/pivot_table/">pivot_table</a>, <a href="/recipes/tags/statistics/">statistics</a>). Revision 9. </p> <p>Simple tool for analyzing datasets.</p>

2005-12-14T20:36:30-08:00Nicolas Lehuenhttp://code.activestate.com/recipes/users/1599156/http://code.activestate.com/recipes/440661-read-tabular-data-from-excel-spreadsheets-the-fast/

<p style="color: grey"> Python recipe 440661 by <a href="/recipes/users/1599156/">Nicolas Lehuen</a> (<a href="/recipes/tags/database/">database</a>). Revision 3. </p> <p>Sometimes you get an Excel spreadsheet (say, from the marketing departement) and you want to read tabular data from it (i.e. a line with column headers and lines of data). There are many ways to do this (including ODBC + mxODBC), but the easiest way I've found is this one : provide a file name and a sheet name, and read the data !</p>

2005-07-22T08:23:58-07:00Sébastien Sauvagehttp://code.activestate.com/recipes/users/2503505/http://code.activestate.com/recipes/438123-file-tkinter-dialogs/

<p style="color: grey"> Python recipe 438123 by <a href="/recipes/users/2503505/">Sébastien Sauvage</a> . </p> <p>Basic Tkinter dialogs for directory selection, file selection and so on. That's dirt simple (although the official documentation is not very explicit about these features).</p>

2003-03-20T10:54:20-08:00Ulrich Hoffmannhttp://code.activestate.com/recipes/users/1056747/http://code.activestate.com/recipes/190465-generator-for-permutations-combinations-selections/

<p style="color: grey"> Python recipe 190465 by <a href="/recipes/users/1056747/">Ulrich Hoffmann</a> (<a href="/recipes/tags/algorithms/">algorithms</a>). </p> <p>Permutations and combinations are often required in algorithms that do a complete search of the solution space. They are typically rather large so it's best not to compute them entirely but better to lazily generate them. This recipe uses Python 2.2 generators to create appropriate generator objects, that can be use for example as ranges in for loops.</p>

2011-08-10T23:54:12-07:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/577834-compare-speeds-of-different-kinds-of-access-to-var/

<p style="color: grey"> Python recipe 577834 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/optimization/">optimization</a>). Revision 5. </p> <p>Compare speeds of locals, nested scopes, global, builtins, instance variables, and class variables.</p>

2012-12-19T07:12:32-08:00Raymond Hettingerhttp://code.activestate.com/recipes/users/178123/http://code.activestate.com/recipes/576694-orderedset/

<p style="color: grey"> Python recipe 576694 by <a href="/recipes/users/178123/">Raymond Hettinger</a> (<a href="/recipes/tags/ordered/">ordered</a>, <a href="/recipes/tags/set/">set</a>). Revision 9. </p> <p>Set that remembers original insertion order.</p>