Generate pot translation file using "mytest" as locale domain:
  xgettext --language=Python --keyword=_:1,2 -d mytest templates/index.html

  If xgettext fails parsing html elements like:
  <input type="submit" value="{{ _('bla') }}" />

  Try --language=Php or something.


Merge against existing pot file:
  msgmerge old.po mytest.po > new.po
  mv new.po mytest.po


Compile:
  msgfmt mytest.po -o locale/{lang}/LC_MESSAGES/mytest.mo


Compile files in this demo:
  msgfmt mytest_pt_BR.po -o frontend/locale/pt_BR/LC_MESSAGES/mytest.mo
  msgfmt mytest_es_ES.po -o frontend/locale/es_ES/LC_MESSAGES/mytest.mo

