Python: Inserting characters between other characters at random points
<p>For example:</p>

<pre><code>str = 'Hello world. Hello world.'
</code></pre>

<p>Turns into:</p>

<pre><code>list = ['!','-','=','~','|']
str = 'He!l-lo wor~ld|.- H~el=lo -w!or~ld.'
</code></pre>

<p>Thanks</p>
