Filtering flight results

Fli provides comprehensive filtering options to help you find exactly the flights you need. All filters can be combined to create highly targeted searches.

Cabin class

Filter flights by cabin class using the SeatType enum:

from fli.models import SeatType, FlightSearchFilters, PassengerInfo, FlightSegment, Airport

filters = FlightSearchFilters(
    passenger_info=PassengerInfo(adults=1),
    flight_segments=[
        FlightSegment(
            departure_airport=[[Airport.JFK, 0]],
            arrival_airport=[[Airport.LAX, 0]],
            travel_date="2026-04-15"
        )
    ],
    seat_type=SeatType.BUSINESS  # Filter for business class
)

Available cabin classes

SeatType.ECONOMY - Economy class (default)
SeatType.PREMIUM_ECONOMY - Premium economy
SeatType.BUSINESS - Business class
SeatType.FIRST - First class

Stops

Control the maximum number of stops using the MaxStops enum:

from fli.models import MaxStops

filters = FlightSearchFilters(
    # ... other parameters
    stops=MaxStops.NON_STOP  # Only direct flights
)

Available stop options

MaxStops.ANY - Any number of stops (default)
MaxStops.NON_STOP - Direct flights only
MaxStops.ONE_STOP_OR_FEWER - Maximum one stop
MaxStops.TWO_OR_FEWER_STOPS - Maximum two stops

The MaxStops enum uses internal values (0-3) but provides descriptive names for clarity.

Airlines

Restrict results to specific airlines by passing a list of Airline enums:

from fli.models import Airline

filters = FlightSearchFilters(
    # ... other parameters
    airlines=[Airline.BA, Airline.VS]  # British Airways and Virgin Atlantic only
)

Common airline codes

View common airline codes

Airline.AA - American Airlines
Airline.BA - British Airways
Airline.DL - Delta Air Lines
Airline.UA - United Airlines
Airline.AF - Air France
Airline.LH - Lufthansa
Airline.VS - Virgin Atlantic
Airline.AC - Air Canada
Airline.JL - Japan Airlines
Airline.QF - Qantas

See the Airline enum for the complete list of supported airlines.

The airlines filter only includes flights operated by the specified carriers. Codeshare flights may not appear in results.

Time windows

Restrict departure and arrival times using TimeRestrictions. All times are in hours from midnight (0-23) in local time:

from fli.models import TimeRestrictions

filters = FlightSearchFilters(
    # ... other parameters
    flight_segments=[
        FlightSegment(
            departure_airport=[[Airport.JFK, 0]],
            arrival_airport=[[Airport.LAX, 0]],
            travel_date="2026-04-15",
            time_restrictions=TimeRestrictions(
                earliest_departure=6,   # 6:00 AM
                latest_departure=10,     # 10:00 AM
                earliest_arrival=12,     # 12:00 PM
                latest_arrival=18        # 6:00 PM
            )
        )
    ]
)

Time restriction parameters

earliest_departure - Earliest departure time (0-23)
latest_departure - Latest departure time (0-23)
earliest_arrival - Earliest arrival time (0-23)
latest_arrival - Latest arrival time (0-23)

All parameters are optional. You can specify only departure times, only arrival times, or any combination.

Complete example with time restrictions

from datetime import datetime, timedelta
from fli.models import (
    Airport,
    FlightSearchFilters,
    FlightSegment,
    PassengerInfo,
    TimeRestrictions,
)
from fli.search import SearchFlights

filters = FlightSearchFilters(
    passenger_info=PassengerInfo(adults=1),
    flight_segments=[
        FlightSegment(
            departure_airport=[[Airport.JFK, 0]],
            arrival_airport=[[Airport.LAX, 0]],
            travel_date=(datetime.now() + timedelta(days=30)).strftime("%Y-%m-%d"),
            time_restrictions=TimeRestrictions(
                earliest_departure=6,  # 6 AM
                latest_departure=10,   # 10 AM
                earliest_arrival=12,   # 12 PM
                latest_arrival=18,     # 6 PM
            ),
        )
    ],
)

search = SearchFlights()
results = search.search(filters)

Sorting

Sort flight results using the SortBy enum:

from fli.models import SortBy

filters = FlightSearchFilters(
    # ... other parameters
    sort_by=SortBy.CHEAPEST  # Sort by lowest price
)

Available sorting options

SortBy.NONE - Default Google Flights sorting (default)
SortBy.TOP_FLIGHTS - Google’s recommended flights
SortBy.CHEAPEST - Lowest price first
SortBy.DEPARTURE_TIME - Earliest departure first
SortBy.ARRIVAL_TIME - Earliest arrival first
SortBy.DURATION - Shortest duration first

The TOP_FLIGHTS option uses Google’s algorithm to balance price, duration, and convenience.

Advanced filtering

Duration limits

Set a maximum total flight duration in minutes:

filters = FlightSearchFilters(
    # ... other parameters
    max_duration=720  # Maximum 12 hours (720 minutes)
)

Layover restrictions

Control layover airports and maximum layover duration:

from fli.models import LayoverRestrictions

filters = FlightSearchFilters(
    # ... other parameters
    layover_restrictions=LayoverRestrictions(
        airports=[Airport.BOS, Airport.ORD],  # Prefer these layover airports
        max_duration=180  # Maximum 3-hour layover (in minutes)
    )
)

Price limits

Set a maximum price for flights:

from fli.models import PriceLimit, Currency

filters = FlightSearchFilters(
    # ... other parameters
    price_limit=PriceLimit(
        max_price=500,
        currency=Currency.USD
    )
)

Currently only USD is supported for price limits.

Combining filters

All filters can be combined for highly specific searches:

from datetime import datetime, timedelta
from fli.models import (
    Airline,
    Airport,
    FlightSearchFilters,
    FlightSegment,
    LayoverRestrictions,
    MaxStops,
    PassengerInfo,
    SeatType,
    TimeRestrictions,
    SortBy,
)
from fli.search import SearchFlights

filters = FlightSearchFilters(
    passenger_info=PassengerInfo(adults=2, children=1, infants_on_lap=1),
    flight_segments=[
        FlightSegment(
            departure_airport=[[Airport.JFK, 0]],
            arrival_airport=[[Airport.LHR, 0]],
            travel_date=(datetime.now() + timedelta(days=30)).strftime("%Y-%m-%d"),
            time_restrictions=TimeRestrictions(
                earliest_departure=8,
                latest_departure=14
            )
        )
    ],
    seat_type=SeatType.BUSINESS,
    stops=MaxStops.ONE_STOP_OR_FEWER,
    airlines=[Airline.BA, Airline.VS],
    max_duration=720,
    layover_restrictions=LayoverRestrictions(
        airports=[Airport.BOS, Airport.ORD],
        max_duration=180
    ),
    sort_by=SortBy.CHEAPEST
)

search = SearchFlights()
results = search.search(filters)

Filter validation

Fli uses Pydantic models to validate all filter parameters. Invalid values will raise a ValidationError:

from pydantic import ValidationError

try:
    filters = FlightSearchFilters(
        passenger_info=PassengerInfo(adults=1),
        flight_segments=[
            FlightSegment(
                departure_airport=[[Airport.JFK, 0]],
                arrival_airport=[[Airport.JFK, 0]],  # Same as departure!
                travel_date="2026-04-15"
            )
        ]
    )
except ValidationError as e:
    print(e)  # "Departure and arrival airports must be different"

Common validation errors include:

Same departure and arrival airports
Travel dates in the past
Invalid time ranges (earliest > latest)
Missing required fields

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Filtering flight results

Cabin class

Available cabin classes

Stops

Available stop options

Airlines

Common airline codes

Time windows

Time restriction parameters

Sorting

Available sorting options

Advanced filtering

Duration limits

Layover restrictions

Price limits

Combining filters

Filter validation

​Cabin class

​Available cabin classes

​Stops

​Available stop options

​Airlines

​Common airline codes

​Time windows

​Time restriction parameters

​Sorting

​Available sorting options

​Advanced filtering

​Duration limits

​Layover restrictions

​Price limits

​Combining filters

​Filter validation

Cabin class

Available cabin classes

Stops

Available stop options

Airlines

Common airline codes

Time windows

Time restriction parameters

Sorting

Available sorting options

Advanced filtering

Duration limits

Layover restrictions

Price limits

Combining filters

Filter validation