How to make python program extensible
<p>So I have a bunch of line of codes like these in a row in my program:</p>

<pre><code>str = str.replace('ten', '10s')
str = str.replace('twy', '20s')
str = str.replave('fy', '40s')
...
</code></pre>

<p>I want to make it such that I don't have to manually open my source file to add new cases. For example ('sy', '70'). I know I have to put all these in a function somehow, but I'd like to map cases that are not in my "mapper lib" from the command line. Configuration file maybe? how? </p>

<p>Thanks!</p>
