title: How to print usage and help from all argparser objects?
body: <p>I have multiple <code>ArgumentParser()</code> in my python script. However, when I run it with <code>-h</code> help is printed only for the first argparser whose arguments got parsed.</p>
  <p>code:</p>
  <pre><code>%%writefile ./test_argparse.py
  import argparse
  ap1 = argparse.ArgumentParser()
  ap1.add_argument(&quot;-a&quot;, &quot;--abcd&quot;, help=&quot;help a&quot;)
  var1 = ap1.parse_known_args()
  ap2 = argparse.ArgumentParser()
  ap2.add_argument(&quot;-e&quot;, &quot;--efgh&quot;, help=&quot;help e&quot;)
  var2 = ap2.parse_known_args()
  </code></pre>
  <p>in shell run:</p>
  <pre><code>python test_argparse.py --help
  </code></pre>
  <p>output:</p>
  <pre><code>usage: test_argparse.py [-h] [-a ABCD]
  
  optional arguments:
    -h, --help            show this help message and exit
    -a ABCD, --abcd ABCD  help a
  
  </code></pre>
  <p>As you can see the usage and help both are displayed only for <code>ap1</code></p>
  <p>I want to be able to display usage and help for both argparsers: <code>ap1</code> and <code>ap2</code>. How can I achieve that?</p>