Variable products importing

Hello,

i would like to ask a quick question.

Imagine you have eshop with shoes, and variable products, and the shoes have sizes for example: S,M,L,XL.
All the sizes have for example 10 patterns, but one of those sizes is missing few patterns, let’s say the size L is missing one or two patterns.

Is there way to not show this pattern when someone will choose size L from dropdown?
It would be great if there would be way to do this while importing csv file with products.

Thank you