title: how to split already opened gvim file
body: <p>So I am using lubuntu and have gvim installed. Suppose I have two files in the current directory, file1.py and file2.py (both python files) and I want to open file1. So I do</p>
  
  <pre><code>gvim file1.py
  </code></pre>
  
  <p>and it opens, which is good. But now suppose I want to open file2.py by vertically (or horizontally) splitting the already open gvim window into two, how would I go about doing so from the terminal?</p>
  
  <p>Also, how do I close only one file which is open splitscreen? So say I have file1.py and file2.py open in one window (vertically split) and I want to close file1.py?</p>