def get_yeast_sequence(chromosome, start, end, reverse_complement=False):
    '''Acquire a sequence from SGD http://www.yeastgenome.org
    :param chromosome: Yeast chromosome.
    :type chromosome: int
    :param start: A biostart.
    :type start: int
    :param end: A bioend.
    :type end: int
    :param reverse_complement: Get the reverse complement.
    :type revervse_complement: bool
    :returns: A DNA sequence.
    :rtype: coral.DNA

    '''
    import requests

    if start != end:
        if reverse_complement:
            rev_option = '-REV'
        else:
            rev_option = ''
        param_url = '&chr=' + str(chromosome) + '&beg=' + str(start) + \
                    '&end=' + str(end) + '&rev=' + rev_option
        url = 'http://www.yeastgenome.org/cgi-bin/getSeq?map=a2map' + \
            param_url

        res = requests.get(url)
        # ok... sadely, I contacted SGD and they haven;t implemented this so
        # I have to parse their yeastgenome page, but
        # it is easy between the raw sequence is between <pre> tags!

        # warning that's for the first < so we need +5!
        begin_index = res.text.index('<pre>')

        end_index = res.text.index('</pre>')
        sequence = res.text[begin_index + 5:end_index]
        sequence = sequence.replace('\n', '').replace('\r', '')
    else:
        sequence = ''

    return coral.DNA(sequence)
Acquire a sequence from SGD http://www.yeastgenome.org
    :param chromosome: Yeast chromosome.
    :type chromosome: int
    :param start: A biostart.
    :type start: int
    :param end: A bioend.
    :type end: int
    :param reverse_complement: Get the reverse complement.
    :type revervse_complement: bool
    :returns: A DNA sequence.
    :rtype: coral.DNA