title: Setting the default value of a function input to equal another input in Python
body: <p>Consider the following function, which does not work in Python, but I will use to explain what I need to do.</p>
  <pre class="lang-py prettyprint-override"><code>def exampleFunction(a, b, c = a):
      ...function body...
  </code></pre>
  <p>That is I want to assign to variable <code>c</code> the same value that variable <code>a</code> would take, unless an alternative value is specified. The above code does not work in python. Is there a way to do this?</p>