def isPalindrome(s, ignorecase=False):

    """
    >>> type(isPalindrome("bob"))
    <type 'bool'>
    >>> isPalindrome("abc")
    False
    >>> isPalindrome("bob")
    True
    >>> isPalindrome("a man a plan a canal, panama")
    True
    >>> isPalindrome("A man a plan a canal, Panama")
    False
    >>> isPalindrome("A man a plan a canal, Panama", ignorecase=True)
    True
    """

    # Create an empty string "onlyLetters"
    # Loop over all characters in the string argument, and add each
    #   character which is a letter to "onlyletters"

    # Reverse "onlyletters" and test if this is equal to "onlyletters"
    onlyLetters = ""
    for char in s:
        if char.isalpha():
            onlyLetters += char

    if onlyLetters[::-1] == onlyLetters and not ignorecase:
        return True
    elif onlyLetters[::-1].upper() == onlyLetters.upper() and ignorecase:
        return True
    else:
        return False