http://code.activestate.com/recipes/tags/functions-objects-trace/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>