title: In vim, how do you add files from the buffer list - that match a pattern - to the arguments list?
body: <p>Say I had opened vim with no arguments, then from within vim opened 10 .txt
  files and 10 .py files. Also, let's say the files are scattered around my file
  system. The buffer list contains all 20 files.</p>
  <p>Now I want to add the 10 .py files to the arguments list. I want to do
  something like <code>:argadd *.py</code>, but this just creates a new file called '*.py'
  and adds it to the arguments list.</p>
  <p>I see from the help that argd[elete] can use a pattern, so I could delete all
  the .py files with <code>:argd *.py</code>. Is there a way to do something similar for
  <code>:arga[dd]</code>?</p>
  <pre><code>:[count]arga[dd] {name} ..
              Add the {name}s to the argument list.  
  
  :argd[elete] {pattern} ..
              Delete files from the argument list that match the
              {pattern}s.
  </code></pre>
  <p>Surely there's a better way than navigating to each .py file and running
  <code>:argadd</code>?</p>