Lists BioMart databases through a RPY2 connection.

    :param host: address of the host server, default='www.ensembl.org'

    :returns: nothing

def RdatabasesBM(host=rbiomart_host):
    """
    Lists BioMart databases through a RPY2 connection.

    :param host: address of the host server, default='www.ensembl.org'

    :returns: nothing

    """
    biomaRt = importr("biomaRt")
    print(biomaRt.listMarts(host=host))