Incorrect test for binary mode in _DownloadReportCheckFormat

[parander]

in adwords.py the method _DownloadReportCheckFormat was recently changed. The new test for is_binary_mode is probably incorrect:

  def _DownloadReportCheckFormat(self, file_format, output):
    is_binary_mode = getattr(output, 'mode', 'w') == 'wb'
    if (file_format.startswith('GZIPPED_')
        and not (is_binary_mode or type(output) is io.BytesIO)):
      raise googleads.errors.GoogleAdsValueError('Need to specify a binary'
                                                 ' output for GZIPPED formats.')

This will incorrectly raise an exception for some valid binary mode combinations (e.g r+b, w+b).

[msaniscalchi]

Hello,

Thanks for the report! It looks like this changed back in July. I don't think we expected the use-case to simultaneously read and write from the downloaded report file during an earlier refactoring, so the logic was simplified to what you see above. That said, I don't see a need for us to restrict this usage, so I think it makes sense to go back and update this. It probably won't make it into the update today, but we'll get around to it soon.

Regards,
Mark

[parander]

I'm actually using a tempfile stream for this, but the 'wb' requirement makes a tempfile useless since it can never be read ;)