title: Skip a specified number of columns with numpy.genfromtxt()
body: <p>I have a large table (numbers in text format) that I would like to load with <code>numpy.genfromtxt()</code>. I would like to ignore the first <em>n</em> columns, say 5. I do not know the size of the table (number of row or columns) in advance.</p>
  
  <p>I saw that <code>genfromtxt()</code> has an option <code>skip_header</code> that allows to skip a specified number of header rows, but it seems there is no such option for columns. There is a <code>usecols</code> option but there I must specify the column numbers I want to keep, rather than those I want to discard (I do not know this number in advance).</p>
  
  <p>Obviously I could just load the whole thing and then throw away the first <em>n</em> columns, but this is not elegant and is wasteful in terms of memory.</p>
  
  <p>Also I could peak into the file, find the number of columns, and then construct the <code>usecols</code> argument, but that is rather messy.</p>
  
  <p>Any ideas on how to solve this elegantly? Is there some hidden/undocumented argument that I can use?</p>