Position pattern matching

I want to look through a list of words and find any that match the pattern of ABCCDAA. How can I do this? Th开发者_如何学Pythonat is, find any words of length 7 whose letters correspond to that pattern (first and last two letters are X, etc).

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regex is simple enough -

/^([a-zA-Z])([a-zA-Z])([a-zA-Z])\3([a-zA-Z])\1\1$/

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Here's my solution:

([a-zA-Z]).([a-zA-Z])\2.\1\1