title: Float values as dictionary key
body: <p>I am developing a class for the analysis of microtiter plates. The samples are described in a separate file and the entries are used for an ordered dictionary. One of the keys is pH, which is usually given as float. e.g 6.8</p>
  
  <p>I could import it as decimal with <code>Decimal('6.8')</code> in order to avoid a float as dict key. Another solution would be to replace the dot with e.g p like 6p8 or to write 6p8 in my sample description and therefore eliminating the problem at the beginning. But this would cause troubles later on since i cannot plot pH of 6p8 in my figures.</p>
  
  <p>How would you solve this issue?</p>