John Mueller from Google announced on Google+ that Google will be discontinuing the support of CSV download scripts, specifically the Python script, to download search query data from Google Search Console, formerly Google Webmaster Tools.
Google said October 20, 2015, is the last day this Python script will work. That should give most webmasters and developers enough time to migrate their scripts over to the new Search Console API.
Google initially launched the download option for Google Webmaster Tools back in December of 2011. So that Python script had about a four-year run, which is not bad at all.
The new Search Console API will provide a more efficient method to grab the same data.
So you have until October 20, 2015, to upgrade your software to the official API.
Postscript: Google, weeks later, posted this news on their blog.