title: pygettext doesn't read strings into the .pot file
body: <p>I try to make a multilingual application with pygettext. I reproduce the steps described here: <a href="https://phrase.com/blog/posts/translate-python-gnu-gettext/" rel="nofollow noreferrer">https://phrase.com/blog/posts/translate-python-gnu-gettext/</a>.</p>
  <p>The translatable strings should appear  at the bottom of the .pot file:</p>
  <pre><code>#: src/main.py:5
  msgid &quot;Hello world&quot;
  msgstr &quot;&quot;
  #: src/main.py:6
  msgid &quot;This is a translatable string&quot;
  msgstr &quot;&quot;
  </code></pre>
  <p>The problem is that in my case there msgid are empty, though .pot file is created.
  It looks like pygettext just doesn't see them in the code.</p>
  <p>That's how my whole .pot file looks like:</p>
  <pre><code># SOME DESCRIPTIVE TITLE.
  # Copyright (C) YEAR ORGANIZATION
  # FIRST AUTHOR &lt;EMAIL@ADDRESS&gt;, YEAR.
  #
  msgid &quot;&quot;
  msgstr &quot;&quot;
  &quot;Project-Id-Version: PACKAGE VERSION\n&quot;
  &quot;POT-Creation-Date: 2021-01-16 13:50+0300\n&quot;
  &quot;PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n&quot;
  &quot;Last-Translator: FULL NAME &lt;EMAIL@ADDRESS&gt;\n&quot;
  &quot;Language-Team: LANGUAGE &lt;LL@li.org&gt;\n&quot;
  &quot;MIME-Version: 1.0\n&quot;
  &quot;Content-Type: text/plain; charset=cp1251\n&quot;
  &quot;Content-Transfer-Encoding: 8bit\n&quot;
  &quot;Generated-By: pygettext.py 1.5\n&quot;
  </code></pre>
  <p>My python code:</p>
  <pre><code># main.py
  import gettext
  _ = gettext.gettext
  
  
  def print_some_strings():
      print(_(&quot;Hello world&quot;))
      print(_(&quot;This is a translatable string&quot;))
  
  
  if __name__ == '__main__':
      print_some_strings()
  </code></pre>
  <p>Project structure:</p>
  <pre><code>pdf_invoices
  │ └── en
  │     └── LC_MESSAGES
  │         └── base.pot
  └──__main__.py
  </code></pre>
  <p>Command creating .pot file:</p>
  <pre><code>C:\&gt;C:\Users\belose\Anaconda3\Tools\i18n\pygettext.py 
  -d C:\Users\belose\PycharmProjects\pdf_invoices\__main__.py 
  -o C:\Users\belose\PycharmProjects\pdf_invoices\locales\ru\base.pot
  </code></pre>