def filter_by_bidder_id(bids, bidder_id):
    """
    >>> bids = [
    ...     {"bidder_id": "1", "amount": 100},
    ...     {"bidder_id": "1", "amount": 200},
    ...     {"bidder_id": "2", "amount": 101}
    ... ]

    >>> filter_by_bidder_id(bids, "1")
    [{'amount': 100, 'bidder_id': '1'}, {'amount': 200, 'bidder_id': '1'}]

    >>> filter_by_bidder_id(bids, "2")
    [{'amount': 101, 'bidder_id': '2'}]

    """
    return [bid for bid in bids if bid['bidder_id'] == bidder_id]