title: square root of a number greater than 10^2000 in Python 3
body: <p>I'd like to calculate the square root of a number bigger than 10^2000 in Python. If I treat this number like a normal integer, I will always get this result back:</p>
  
  <pre><code>Traceback (most recent call last):
    File "...", line 3, in &lt;module&gt;
      print( q*(0.5)  )
  OverflowError: int too large to convert to float
  </code></pre>
  
  <p>How do I fix this? Or does a possibilty other than using Python exist to calculate this square root?</p>