python 3: how to make strip() work for bytes

I've contered a Python 2 code to Python 3. In doing so, I've changed

print 'String: ' + somestring

into

print(b'String: '+somestring)

because I was getting the following error:

Can't convert 'bytes' object to str implicitly

But then now I can't implement string attributes such as strip(), because they are no longer treated as strings...

global name 'strip' is not defined 

for

if strip(somestring)=="":    

How should I solve this dilemma between switching string to bytes and being able to use string attributes? Is there a workaround? Please help me out and thank you in advance..