regex - selecting words that only have specific letters in them -

i trying print words match regex provide , contain letters provided in second parameter. regex works perfectly, letter selection not.

import re  def search(regex,letters):     letters=set(letters)     pattern=re.compile(regex)     word in content:         word=word.strip()         if(pattern.findall(word)):             if letters & set(word):                 print(word)   #search(r'^(n|u|p|g|o|u|e|b|l){6}$') #search(r'^t(i|a)[a-z]{3}') content=["hello","helps","halts","random"] search(r'^h(e|a)[a-z]{3}','hltsa') #returns: hello,helps,halts 

my goal return halts, because matches second parameter.

import re  def search(regex,letters):     letters=set(letters)     pattern=re.compile(regex)     word in content:         word=word.strip()         if(pattern.findall(word)):             if set(word) >= letters:                 print(word)   #search(r'^(n|u|p|g|o|u|e|b|l){6}$') #search(r'^t(i|a)[a-z]{3}') content=["hello","helps","halts","random"] search(r'^h(e|a)[a-z]{3}','hltsa') #returns: hello,helps,halts 

try this, changed if letters & set(word):

in documentation sets can find this

s.issubset(t)    s <= t  test whether every element in s in t s.issuperset(t)  s >= t  test whether every element in t in s