title: Looking for Fast log10floor implementation for Python
body: <p>Is there any library that implements an efficient <code>log10floor</code> function in Python?</p>
  
  <p>Python has <a href="https://stackoverflow.com/questions/931995/inaccurate-logarithm-in-python">accuracy problems for large numbers</a>, but if one simply rounds a logarithm to its floor, then it's possible to have a very simple implementation. I'd rather not code my own, so I'm looking for one.</p>
  
  <p>As an example for Java, Guava implements <a href="https://github.com/google/guava/blob/master/guava/src/com/google/common/math/LongMath.java#L162" rel="nofollow noreferrer">a very fast <code>log10</code> function</a> when you want to round to floor.</p>