Capitalise a varying phrase in same position in Terminal

Question

I have a number of .py files that contain a line like this:

self._cols = [self.foo.bar.relevant_string.str()]

I need to capitalise the relevant_string, to get this

self._cols = [self.foo.bar.RELEVANT_STRING.str()]

in all ~100 of them.

Is there a way to do this with bash/awk/perl? I tried something like this

perl  -pe 's/self.foo.bar./uc($&)/e' *.py

But it capitalised the captured area, not the part after.

Answer 1

With GNU sed:

$ echo 'self._cols = [self.foo.bar.relevant_string.str()]' |
    sed -E 's/(self\.foo\.bar\.)([^.]+)/\1\U\2/'
self._cols = [self.foo.bar.RELEVANT_STRING.str()]