I trying the duplicate_encode kata for Python.

Despite all test are ok, when trying the final attemp it gives me an error in the last test, it returns:

 '))(()())())' should equal '()(((())())'

My code is:

 def duplicate_encode(word):
   nword=''
   for c in word.lower():nword+='(' if word.count(c)==1 else ')' 
   return nword

I do not have feedback of the input that gives error. Can someone help me please?

Thanks.