title: How do I create a numpy array from string?
body: <p>I have a file reader that reads <em>n</em> bytes from a file and returns a string of chars representing that (binary) data. I want to read up <em>n</em> bytes into a numpy array of numbers and run a FFT on it, but I'm having trouble creating an array from a string.  A couple lines of example would be awesome.</p>
  
  <p><strong>Edit:</strong>
  I'm reading raw binary data, and so the string I get looks like <code>'\x01\x05\x03\xff'...</code>.  I want this to become <code>[1, 5, 3, 255]</code>.</p>