House Comparison #

The HouseComparisonFactory performs bidirectional house overlay analysis between two subjects. It calculates where each person’s planets and cusps fall in the other person’s house system.

This is a key technique in synastry interpretation — knowing that someone’s Venus falls in your 7th house, or their Sun lands in your 10th house, provides specific relational context.

Basic Usage #

from kerykeion import AstrologicalSubjectFactory, HouseComparisonFactory

person_a = AstrologicalSubjectFactory.from_birth_data(
    "Alice", 1990, 6, 15, 12, 0,
    lng=12.4964, lat=41.9028, tz_str="Europe/Rome", online=False,
)
person_b = AstrologicalSubjectFactory.from_birth_data(
    "Bob", 1988, 11, 22, 9, 30,
    lng=-0.1278, lat=51.5074, tz_str="Europe/London", online=False,
)

factory = HouseComparisonFactory(person_a, person_b)
comparison = factory.get_house_comparison()

print(f"Comparison: {comparison.first_subject_name} <-> {comparison.second_subject_name}")

Understanding the Results #

The HouseComparisonModel contains four lists for bidirectional analysis:

Points in Partner’s Houses #

Where each person’s planets fall in the other’s house system:

# Alice's planets in Bob's houses
print("\nAlice's planets in Bob's houses:")
for point in comparison.first_points_in_second_houses:
    print(f"  {point.point_name} -> Bob's House {point.projected_house_number}")

# Bob's planets in Alice's houses
print("\nBob's planets in Alice's houses:")
for point in comparison.second_points_in_first_houses:
    print(f"  {point.point_name} -> Alice's House {point.projected_house_number}")

Cusps in Partner’s Houses #

Where each person’s house cusps fall in the other’s system:

# Alice's cusps in Bob's houses
print("\nAlice's cusps in Bob's houses:")
for cusp in comparison.first_cusps_in_second_houses:
    print(f"  House {cusp.point_owner_house_number} cusp -> Bob's House {cusp.projected_house_number}")

# Bob's cusps in Alice's houses
print("\nBob's cusps in Alice's houses:")
for cusp in comparison.second_cusps_in_first_houses:
    print(f"  House {cusp.point_owner_house_number} cusp -> Alice's House {cusp.projected_house_number}")

Using with Synastry Charts #

HouseComparisonFactory is used internally by ChartDataFactory when generating synastry, transit, and dual return chart data. You can also use it standalone for data analysis:

from kerykeion import AstrologicalSubjectFactory, ChartDataFactory, HouseComparisonFactory

alice = AstrologicalSubjectFactory.from_birth_data(
    "Alice", 1990, 6, 15, 12, 0,
    lng=12.4964, lat=41.9028, tz_str="Europe/Rome", online=False,
)
bob = AstrologicalSubjectFactory.from_birth_data(
    "Bob", 1988, 11, 22, 9, 30,
    lng=-0.1278, lat=51.5074, tz_str="Europe/London", online=False,
)

# Standalone house comparison
comparison = HouseComparisonFactory(alice, bob).get_house_comparison()

# Or via ChartDataFactory (comparison is included in the chart data)
synastry_data = ChartDataFactory.create_synastry_chart_data(alice, bob)

Constructor Parameters #

Parameter	Type	Default	Description
`first_subject`	`AstrologicalSubjectModel` or `PlanetReturnModel`	Required	First subject
`second_subject`	`AstrologicalSubjectModel` or `PlanetReturnModel`	Required	Second subject
`active_points`	`list[AstrologicalPoint]`	`DEFAULT_ACTIVE_POINTS`	Which points to include

Return Model #

get_house_comparison() returns a HouseComparisonModel with:

Field	Type	Description
`first_subject_name`	`str`	Name of the first subject
`second_subject_name`	`str`	Name of the second subject
`first_points_in_second_houses`	`list`	First subject’s points placed in second’s houses
`second_points_in_first_houses`	`list`	Second subject’s points placed in first’s houses
`first_cusps_in_second_houses`	`list`	First subject’s cusps placed in second’s houses
`second_cusps_in_first_houses`	`list`	Second subject’s cusps placed in first’s houses

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