title: numpy.loadtxt gives "not iterable" error
body: <p>I'm trying to use <code>numpy.loadtxt</code> to read the data in a file that looks like this:</p>
  
  <pre><code>## 14 line of header
  3 0 36373.7641026
  3 1 36373.7641026
  3 2 36373.7641026
  ...
  </code></pre>
  
  <p>And when I give it this:</p>
  
  <pre><code>&gt;&gt;&gt; chunk, power = numpy.loadtxt(bf,skiprows=14,usecols=(1,2),unpack=True)
  </code></pre>
  
  <p>Or even this:</p>
  
  <pre><code>&gt;&gt;&gt; power = numpy.loadtxt(bf,skiprows=14,usecols=(2))
  </code></pre>
  
  <p>It says, <code>TypeError: 'int' object is not iterable</code></p>
  
  <p>I assumed it was because the first two columns were clearly integers not float, but now I'm not even sure which int object it's referring, because it won't even read just the floats. How do I make <code>loadtxt</code> work?</p>
  
  <p>Related: How do I specify the format of multiple columns using <code>dtype = ?</code> I'm having trouble figuring it out via google.</p>