def simple_copy(data, conn, name=None, null_values=None):
    """
    Copy a Table into a Postgres database
     * Does not create table (should be done beforehand)
     * Does not make sure the schemas match (should be done beforehand)
     * Does not auto-commit
     
    Parameters
    -----------
    data:           Table or StringIO
    name:           str
                    Name of the Table to COPY to
    null_values:    str
                    String representing null values
    conn:           psycopg2 connection
    """
    name = data.name
    stringio_ = data.to_string()
    if null_values:
        copy_from = (
            "COPY {0} FROM STDIN (FORMAT csv, DELIMITER ',', NULL '{1}')".
            format(name, null_values))
    else:
        copy_from = "COPY {0} FROM STDIN (FORMAT csv, DELIMITER ',')".format(
            name)
    stringio_.seek(0)
    conn.cursor().copy_expert(copy_from, file=stringio_)
