Is it possible to use the difference between two characters set as one character set in regex?

Question

Suppose I have a character set [ancde]. Now, I want to print the words of a sentence where the first character is a word character which is any word character except [ancde] and then the next two character to match is 'at'
so if there is a sentence that has "aat dat vat cat bat tat dat fat fet ere tyy jat nat dat",

The following pattern list will be ['vat', 'bat', 'tat', 'fat', 'jat']
I can do this by comparing with \W(isn't word char)
https://code.sololearn.com/c85vPGc8HKy9
But I want something like we use in set {1,2,3,4,5}-{1,3,4}={2,5}
So is it possible to directly use the difference of \w character and the char set [ancde]?
Thank you and sorry for my bad English.

Answer 1

You can fake a set intersection using positive lookahead.

r'(?=\w)[^ancde]at'

The bracket with ?= will check if the next character is a word character without actually consuming the character.

If the lookahead matches, the string will be matched against [^ancde] which does just what you would expect.

Answer 2

I see .That's the thing I was looking for.Thank you very much @Schindlabua