Why is Vigenere cipher only encrypting part of message properly?

Question

Why is Vigenere cipher only encrypting part of message properly? We started off writing a Caesar cipher and graduated to a Vigenere cipher using the helper functions created for Caesar. My alphabet_position and rotate_character functions seem to be working, however my encrypt function for Vigenere is only returning part of the encrypted message properly.
For example, print encrypt('BaRFoo',Baz) should have returned: 'CaQGon' actually returned: 'CakGo\x88'

Below is my code so far:

import string

def alphabet_position(letter):
    return (ord(letter))

def rotate_character(char,rot):
    encoded = ""
    # loop over characters for ord
    char_ord = alphabet_position(char)
    # non-alphabet characters
    if (char_ord > 90 and char_ord < 97) or char_ord < 65 or char_ord >122:
        encoded = encoded + char
        return encoded
    else:
        # set each according to whether upper or lower case
        # ord of "Z" is 90, so 91 for upper range and ord of "A" is 65 so 
        uppercase boundary
        if char.isupper():
            asciirange = 91
            asciibound = 65
        else:
            # ord of "z" is 122 so 123 for upper range and ord of "a" is 97 
            so lowercase boundary
            asciirange = 123
            asciibound = 97

    enc_char = ((char_ord + rot) % asciirange)
    if enc_char < asciibound:
       enc_char = (enc_char + asciibound)
       encoded = encoded + (chr(enc_char))
    else:
       encoded = encoded + (chr(enc_char))
    return (encoded)

def encrypt(text,keyword):
    encoded_text = ""
    key_start = 0
    # find rot
    alpha = string.ascii_letters
    for char in text:
        # check if char is a letter
        if char.isalpha():
            key_num = (alphabet_position(keyword[key_start]))
            # convert key_num to a letter to find its index
            rot = alpha.find(chr(key_num))
            encoded_text += (rotate_character(char,rot))
            if key_start == (len(keyword)-1):
                key_start = 0
            else:
                key_start += 1
         else:
             encoded_text += char

    return encoded_text

Answer 1

for index, char in enumerate(text):
    print index, char

Sorry, I'm not sure this is what you asked for, but i try ;) Hope it helps.