http://code.activestate.com/recipes/tags/functions-objects/2017-04-19T18:03:11-07:00ActiveState Code Recipes2017-04-19T18:03:11-07:00Vasudev Ramhttp://code.activestate.com/recipes/users/4173351/http://code.activestate.com/recipes/580787-implementing-function-based-callbacks-in-python/

<p style="color: grey"> Python recipe 580787 by <a href="/recipes/users/4173351/">Vasudev Ram</a> (<a href="/recipes/tags/callback/">callback</a>, <a href="/recipes/tags/function/">function</a>, <a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/python/">python</a>, <a href="/recipes/tags/techniques/">techniques</a>). </p> <p>This recipe shows a simple way of implementing callbacks in Python. There are a few ways this can be done. The way shown here uses a simple function-based approach.</p> <p>In a nutshell, a callback can be informally described like this: function <strong>a</strong> calls function <strong>b</strong>, and wants to make <strong>b</strong> run a specific independent chunk of code at some point during <strong>b</strong>'s execution. We want to be able to vary which chunk of code gets called in different calls to <strong>b</strong>, so it cannot be hard-coded inside <strong>b</strong>. So function <strong>a</strong> passes another function, <strong>c</strong>, to <strong>b</strong>, as one argument, and <strong>b</strong> uses that parameter <strong>c</strong> to call the functionality that <strong>a</strong> wants <strong>b</strong> to call. (Function <strong>b</strong> may pass some parameters to the function represented by <strong>c</strong>, when it calls it. These could be either internally generated, passed from <strong>a</strong>, or a combination of both). So, by changing the value of the function <strong>c</strong> that gets passed to <strong>b</strong> (on different calls to <strong>b</strong>), <strong>a</strong> can change what chunk of code <strong>b</strong> calls.</p> <p>More details and full code, description and output here:</p> <p><a href="https://jugad2.blogspot.in/2017/04/implementing-and-using-callbacks-in.html" rel="nofollow">https://jugad2.blogspot.in/2017/04/implementing-and-using-callbacks-in.html</a></p>

2017-01-30T14:09:47-08:00Vasudev Ramhttp://code.activestate.com/recipes/users/4173351/http://code.activestate.com/recipes/580753-find-the-arity-of-a-python-function/

<p style="color: grey"> Python recipe 580753 by <a href="/recipes/users/4173351/">Vasudev Ram</a> (<a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/introspection/">introspection</a>, <a href="/recipes/tags/python/">python</a>, <a href="/recipes/tags/python2/">python2</a>, <a href="/recipes/tags/reflection/">reflection</a>). </p> <p>This recipe shows how to find the arity of a given Python function. The arity of a function is the number of arguments the function takes. The recipe uses the inspect module of Python.</p> <p>More details and sample output (including some limitations) here:</p> <p><a href="https://jugad2.blogspot.in/2017/01/finding-arity-of-python-function.html" rel="nofollow">https://jugad2.blogspot.in/2017/01/finding-arity-of-python-function.html</a></p>

2011-08-12T23:06:57-07:00Eric Snowhttp://code.activestate.com/recipes/users/4177816/http://code.activestate.com/recipes/577786-smarter-default-arguments/

<p style="color: grey"> Python recipe 577786 by <a href="/recipes/users/4177816/">Eric Snow</a> (<a href="/recipes/tags/default_arguments/">default_arguments</a>, <a href="/recipes/tags/deferred/">deferred</a>, <a href="/recipes/tags/function/">function</a>, <a href="/recipes/tags/functions/">functions</a>). Revision 3. </p> <p>Improved handling of mutable and deferred default arguments. After the recipe you'll find an explanation of what that means.</p> <p>Works for 2.7 with minor tweaks (getfullargspec --> getargspec).</p>

2011-10-05T18:38:43-07:00Eric Snowhttp://code.activestate.com/recipes/users/4177816/http://code.activestate.com/recipes/577822-turn-a-function-into-a-class/

<p style="color: grey"> Python recipe 577822 by <a href="/recipes/users/4177816/">Eric Snow</a> (<a href="/recipes/tags/classes/">classes</a>, <a href="/recipes/tags/functions/">functions</a>). </p> <p>The only catch is that the function has to return locals() at the end. And it doesn't do the __prepare__ part of 3.x metaclasses.</p>

2011-07-18T15:11:51-07:00Dominic Innocenthttp://code.activestate.com/recipes/users/4178543/http://code.activestate.com/recipes/577799-batting-ball/

<p style="color: grey"> Python recipe 577799 by <a href="/recipes/users/4178543/">Dominic Innocent</a> (<a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/simple/">simple</a>). </p> <p>Have fun batting a ball about a room &amp; sometimes getting funny results.</p>

2011-01-24T18:40:51-08:00Kevin L. Sitzehttp://code.activestate.com/recipes/users/4173535/http://code.activestate.com/recipes/577551-trace-decorator-for-debugging/

<p style="color: grey"> Python recipe 577551 by <a href="/recipes/users/4173535/">Kevin L. Sitze</a> (<a href="/recipes/tags/classes/">classes</a>, <a href="/recipes/tags/debug/">debug</a>, <a href="/recipes/tags/debugging/">debugging</a>, <a href="/recipes/tags/decorators/">decorators</a>, <a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/inspection/">inspection</a>, <a href="/recipes/tags/modules/">modules</a>, <a href="/recipes/tags/trace/">trace</a>). Revision 2. </p> <p>This package provides a decorator for tracing function and method calls in your applications. The tracing capabilities are managed through the logging package, and several mechanisms are provided for controlling the destination of the trace output.</p> <p>It also provides functionality for adding decorators to existing classes or modules.</p>