Python

How do you append to a file?

<p>How do you append to the file instead of overwriting it? Is there a special function that appends to the file?</p> <p><br><br><br><h1>Answer</h1></p> <pre><code>with open(&amp;#34;test.txt&amp;#34;, &amp;#34;a&amp;#34;) as myfile: myfile.wri

Python division

<p>I was trying to normalize a set of numbers from -100 to 0 to a range of 10-100 and was having problems only to notice that even with no variables at all, this does not evaluate the way I would expect it to:</p> <pre><code>&amp;gt;&amp;gt;&amp;gt;

What is the purpose of self?

<p>What is the purpose of the <span class="inlinecode">self</span> word in Python? I understand it refers to the specific object created from that class, but I can&rsquo;t see why it explicitly needs to be added to every function as a parameter. To

How do I parse XML in Python?

<p>I have many rows in a database that contains xml and I&rsquo;m trying to write a Python script that will go through those rows and count how many instances of a particular node attribute show up. For instance, my tree looks like:</p> <pre><code>&

Reverse a string in Python

<p>There is no built in <span class="inlinecode">reverse</span> function in Python&rsquo;s <span class="inlinecode">str</span> object. What is the best way of implementing this?</p> <p>If supplying a very concise answer, please elaborate on it&rsq

Explain slice notation

<p>I need a good explanation (references are a plus) on Python&rsquo;s slice notation.</p> <p>To me, this notation needs a bit of picking up.</p> <p>It looks extremely powerful, but I haven&rsquo;t quite got my head around it.</p> <p><br><br><br><

What is __init__.py for?

<p>What is <span class="inlinecode"><strong>init</strong>.py</span> for in a Python source directory?</p> <p><br><br><br><h1>Answer</h1> It&rsquo;s a part of a package. <a href="http://docs.python.org/tutorial/modules.html#packages" rel="noreferrer