docs: def source(fname):
      '''
      Acts similar to bash 'source' or '.' commands.
      '''
      rex = re.compile('(?:export |declare -x )?(.*?)="(.*?)"')
      out = call_out('source {} && export'.format(fname))
      out = [x for x in out if 'export' in x or 'declare' in x]
      out = {k: v for k, v in [rex.match(x).groups() for x in out if rex.match(x)]}
      for k, v in out.items():
          os.environ[k] = v