title: downloading a file, not the contents
body: <p>I am trying to automate downloading a .Z file from a website, but the file I get is 2kb when it should be around 700 kb and it contains a list of the contents of the page (ie: all the files available for download).  I am able to download it manually without a problem.  I have tried urllib and urllib2 and different configurations of each, but each does the same thing. I should add that the urlVar and fileName variables are generated in a different part of the code, but I have given an example of each here to demonstrate.</p>
  
  <pre><code>import urllib2
  urlVar = "ftp://www.ngs.noaa.gov/cors/rinex/2014/100/txga/txga1000.14d.Z"
  fileName = txga1000.14d.Z
  downFile = urllib2.urlopen(urlVar)
  with open(fileName, "wb") as f:
      f.write(downFile.read())
  </code></pre>