title: more decimal places needed in python
body: <p>I am writing a python code, which needs to asses number to very many decimal places - around 14 or 15.</p>
  
  <p>I expect results that increase smoothly, for example:</p>
  
  <pre><code>0.123456789101997
  0.123456789101998
  0.123456789101999
  0.123456789102000
  0.123456789102001
  </code></pre>
  
  <p>But I seem to be only getting numbers (when I print them out) to 12 decimal places, so my numbers are actually jumping in steps:</p>
  
  <pre><code>0.123456789101
  0.123456789101
  0.123456789101
  0.123456789102
  0.123456789102
  </code></pre>
  
  <p>At first, I assumed that the number was listed to more decimal places behind the scenes, but just printed out to 12, but when I print the results, they seem to plot in steps also, rather than smoothly.</p>
  
  <p>I'd be really grateful if anyone would point me in the right direction to fix this - thank you.</p>