my_data = {'2021-01-01': 'data1',
           '2021-02-22': 'data2',
           '2021-03-11': 'data3',
           '2021-03-12': 'data4',
           '2021-12-30': 'data5'}


def data_search(my_data, start_data, end_data):
    my_data_selected = {}
    start_value = start_data[5:7] + start_data[-2:]
    end_value = end_data[5:7] + end_data[-2:]
    my_data_selected = {key: my_data[key] for key in my_data.keys()
                        if start_value <= key[5:7] + key[-2:] <= end_value}
    """for key in my_data.keys():
        if start_value <= key[5:7]+ key[-2:] <= end_value:
            my_data_selected[key] = my_data[key]"""
    return my_data_selected


if __name__ == '__main__':
    selection = data_search(my_data, '2021-01-01', '2021-09-01')
    print(selection)
    assert data_search(my_data, '2021-01-01', '2021-01-01') == {'2021-01-01': 'data1'}
    assert data_search(my_data, '2021-02-02', '2021-02-30') == {'2021-02-22': 'data2'}
    assert data_search(my_data, '2021-03-12', '2021-12-30') == {'2021-03-12': 'data4', '2021-12-30': 'data5'}