title: Python: Make this code more compact?
body: <p>How can I get rid of the excessive repetition in this code?</p>
  
  <p>Code: <a href="http://pastebin.com/13e2nWM9" rel="nofollow">http://pastebin.com/13e2nWM9</a></p>
  
  <p>The program calculates equations of motion (SUVAT Equations) based on data provided by the user.</p>
  
  <p>The section I refer to is:</p>
  
  <pre><code>while True:
          a = raw_input("What is the value of a? Make sure it is in standard units, however, do not include the unit.")
          try:
              float(a)
              print "a is " + str(a) + " ms^-2"
              break
          except:
              print"You must enter a number. Don't include units!"
  </code></pre>
  
  <p>This is repeated many times, save for the variable 'a' and the unit which changes when the block is repeated.</p>
  
  <p>Many thanks.</p>