code: def _parse(self, fp):
          
          for line in fp:
              # '   #export foo=some var  ' -> ['#export', 'foo=some var  ']
              bits = shlex_split(line, comments=True)
              if (not bits) or bits[0].startswith('#'):
                  continue
  
              if bits[0] == u'export':
                  bits.pop(0)
  
              key, sep, value = str_partition(u' '.join(bits), u'=')
              if key and sep:
                  yield key, value
docs: linux-pam-1.3.1/modules/pam_env/pam_env.c#L207