hash.py

import hashlib

valid_types=[ 'md5', 'sha1', 'ripemd160', 'sha224', 'sha256', 'sha384', 'sha512']
hash_type=None

while hash_type!="exit":
    hash_type=raw_input("Enter hash type -- valid are: {}\n>>>".format(
                                                    ', '.join(valid_types))).lower()
    if hash_type in valid_types:
        hashed=hashlib.new(hash_type)
        hashed.update(raw_input("'Enter your string\n>>>"))
        print hashed.hexdigest()
    elif hash_type=="exit":
        print "Bye!"
    else:
        print "Invalid input only {} is allowed".format(', '.join(valid_types))