Retrieve information.

def communicate(self):
        """Retrieve information."""
        self._communicate_first = True
        self._process.waitForFinished()

        if self._partial_stdout is None:
            raw_stdout = self._process.readAllStandardOutput()
            stdout = handle_qbytearray(raw_stdout, _CondaAPI.UTF8)
        else:
            stdout = self._partial_stdout

        raw_stderr = self._process.readAllStandardError()
        stderr = handle_qbytearray(raw_stderr, _CondaAPI.UTF8)
        result = [stdout.encode(_CondaAPI.UTF8), stderr.encode(_CondaAPI.UTF8)]

        # FIXME: Why does anaconda client print to stderr???
        if PY2:
            stderr = stderr.decode()
        if 'using anaconda' not in stderr.lower():
            if stderr.strip() and self._conda:
                logger.error('{0}:\nSTDERR:\n{1}\nEND'.format(
                        ' '.join(self._cmd_list), stderr))
            elif stderr.strip() and self._pip:
                logger.error("pip error: {}".format(self._cmd_list))
        result[-1] = ''

        if self._parse and stdout:
            try:
                result = json.loads(stdout), result[-1]
            except Exception as error:
                result = stdout, str(error)

            if 'error' in result[0]:
                if not isinstance(result[0], dict):
                    result = {'error': str(result[0])}, None
                error = '{0}: {1}'.format(" ".join(self._cmd_list),
                                          result[0]['error'])
                result = result[0], error

        if self._callback:
            result = self._callback(result[0], result[-1],
                                    **self._extra_kwargs), result[-1]

        self._result = result
        self.sig_finished.emit(self, result[0], result[-1])

        if result[-1]:
            logger.error(str(('error', result[-1])))

        self._fired = True

        return result