title: Python float to string: how to get '0.03' but '-.03'
body: <p>Is there a quick way to convert a floating point number between -0.99 and +0.99 such that it always takes up 4 characters: ie positive values go to e.g. '0.03' but negative values to e.g. '-.03', without the leading zero?
  Obviously I could do</p>
  
  <pre><code>s = '%4.2f' % n
  if s[0] == '-':
      s = '-%s' % s[2:]
  </code></pre>
  
  <p>but perhaps some stackoverflowers know of a Python shortcut?</p>