linux - grep for only uppercase words -

i find words all uppercase, when do

grep -op '\w*[a-z]+\w*' * 

i get

words.py:stringvalue words.py:words words.py:words_answered words.py:answered words.py:true 

where hoping for

words.py:words words.py:words_answered 

question

how can make sure uppercase words outputted?

you can use regex word boundary on either side , using [a-z0-9_] instead of \w:

grep -h -op '\b[a-z0-9_]*[a-z]+[a-z0-9_]*\b' *  words.py:words words.py:words_answered