You will learn python, but Django is it’s own beast. If you are experienced in another language or web programming then you will be fine jumping into Django. If this is your first language then you need to learn basic python first .
Read moreIs it necessary to learn HTML before Django?
No it is not necessary to know html/css, if you are learning Django/Flask . But it depends on which kind of team you are working. If have a large number of people working in your team, you can give the work related to html/css to a specific person specialized in html/css.
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