Talk proposals should have one or more tags. Please leave a space between each tag. Do not separate them with commas or fullstops. And please, please do not use the word 'python' as a tag. If you are talking about some exotic python version, do a tag like python4.1 and not 'python 4.1'. Those who have put commas or the word python in their tags are requested to edit them out. Thank you for your attention.