From personal experience...
Raspberries are extremely invasive so be warned. They set deep tap roots for anchorage and shallow rooted runners that sprout new shouts all the way along.
It's nigh on impossible to contain Raspberries and they will come up anywhere and everywhere, growing twenty feet from the parent plant with no distinction between lawn, paving or the neighbour's lawn!
So, what to do about this?
Some gardeners mow the grass verges where Raspberries grow whilst others sink concrete slabs, neither of which deters the runners, only maintains an appearance.
I must say, this does annoy me about gardener's world, when they show and tell you what to do with raspberries but never breath a word about their vigour.
In the Elizabethan days, Raspberries were the woodland bramble and Blackberries were the fruit of cultivation. How things have changed but at least Blackberries can be contained since they root from their tips, not by stealth underground.
Personally, I dug all mine out after three years of ignorance that saw one single plant turn into a forest and I still have the odd rouge sprout that needs hacking back.
I would only grow Raspberries in pots if I chose to love these thugs again. Good Luck with yours.