#String, String -> String
def removeMatches(myString, removeString):
    """This method removes the letter from myString that are also letters in removeString"""
    newStr = ""
    for ch in myString:
        if ch not in removeString:
            newStr = newStr + ch
    return newStr

#String -> String
def removeDupes(myString):
    """This function removes the duplicate characters from a string"""
    newStr = ""
    for ch in myString:
        if ch not in newStr:
            newStr = newStr + ch
    return newStr

#String -> String
def genKeyFromPass(password):
    """This function generates a key from user's password"""
    key = "abcdefghijklmnopqrstuvwxyz"
    password = removeDupes(password)
    lastChar = password[-1]
    lastIdx = key.find(lastChar)
    afterString = removeMatches(key[lastIdx+1:], password)
    beforeString = removeMatches(key[:lastIdx],password)
    key = password + afterString + beforeString
    return key