title: how to find substrings at the start of a main string when match does not work
body: <p>I want to search for one string at the beginning of another in Python 3.x</p>
  
  <p>so I have </p>
  
  <pre><code>for pattern, responses in substrings:
      match = re.match(pattern, statement)
      if match: # etc.
  </code></pre>
  
  <p>But
  if one of substrings is <code>'no'</code> this will be found not only if the first word is 'no' but also if it is <code>'noggin'</code> for example</p>
  
  <p>How can I search for the <code>'no'</code> at the start only if the word is <code>'no'</code>?</p>
  
  <p>Thank you</p>