def variants_chrpos(chrpos, radius=0):
    """This function returns the dbSNP rsid for a single variant in chr:pos format

    Parameters:
        chrpos: variant in chr:pos format (string)

    Returns:
        data: variant rsid (string)

    """
    import ieugwaspy.query as query
    variantdata = query.api_query('variants/chrpos/{}'.format(chrpos))
    result = variantdata[0][0]['_id']
    return result
