Update protein_analysis.py

I think there is a misunderstanding of python's built-in type() method. All type(x) does is return the datatype of the object passed. That is why it is returning the value "<str>".

https://docs.python.org/2/library/functions.html#type
http://www.diveintopython.net/power_of_introspection/built_in_functions.html#d0e8510