List of dictionaries, remove dicts with some duplicate key, values

Removing duplicates from list of dicts is as simple as set(list) but i have got stuck with this specific task.

I need to filter a list of dicts only by some keys and keep only the first elements

flights = [
    {
        'dep_code': 'LON',
        'arr_code': 'PAR',
        'airline': 'BA',
        'date': '2022-07-07'
    },
    {
        'dep_code': 'LON',
        'arr_code': 'PAR',
        'airline': 'BA',
        'date': '2022-08-07'
    },
    {
        'dep_code': 'LON',
        'arr_code': 'PAR',
        'airline': 'BA',
        'date': '2022-09-07'
    },
    {
        'dep_code': 'LON',
        'arr_code': 'BRU',
        'airline': 'BA',
        'date': '2022-10-07'
    },
    {
        'dep_code': 'LON',
        'arr_code': 'BRU',
        'airline': 'BA',
        'date': '2022-11-07'
    },
]

I need to get this very result (keep only first elements with same ‘dep_code’ and ‘arr_code’)

flights = [
    {
        'dep_code': 'LON',
        'arr_code': 'PAR',
        'airline': 'BA',
        'date': '2022-07-07'
    },
    {
        'dep_code': 'LON',
        'arr_code': 'BRU',
        'airline': 'BA',
        'date': '2022-10-07'
    },
]

Thanks for your time!

Answer

You need to save all found data in a list.

found = list()
result = list()
for d in flights:
    if not [d['dep_code'],d['arr_code']] in found:
        result.append(d)
        found.append([d['dep_code'],d['arr_code']])
print(result)