title: Find the similarity metric between two strings
body: <p>How do I get the probability of a string being similar to another string in Python?</p>
  
  <p>I want to get a decimal value like 0.9 (meaning 90%) etc. Preferably with standard Python and library.</p>
  
  <p>e.g.</p>
  
  <pre><code>similar("Apple","Appel") #would have a high prob.
  
  similar("Apple","Mango") #would have a lower prob.
  </code></pre>