Configuration

ascendant.configuration owns the process-wide defaults used when a new Ascendant instance does not receive an explicit ayanamsa or house system. The configuration is one frozen AscendantConfig; calling configure() replaces that complete value.

Configure new instances

from ascendant import (
    AscendantConfig,
    Ayanamsa,
    HouseSystem,
    configure,
)

config = AscendantConfig(
    ayanamsa=Ayanamsa.RAMAN,
    house_system=HouseSystem.PORPHYRY,
)
configure(config)

AscendantConfig is frozen and slotted. Its fields accept enum members, not arbitrary strings. Passing a dictionary or another object to configure() raises TypeError; passing strings into AscendantConfig also raises TypeError.

The built-in value is equivalent to:

AscendantConfig(
    ayanamsa=Ayanamsa.LAHIRI,
    house_system=HouseSystem.WHOLE_SIGN,
)

Read and reset the configuration

from ascendant import get_config, reset_config

current = get_config()
print(current.ayanamsa)
print(current.house_system)

reset_config()

get_config() returns the current immutable object. reset_config() replaces it with a new default AscendantConfig, restoring Lahiri and Whole Sign. Reads and replacements are protected by a lock, so callers do not observe a partially changed configuration.

How an instance resolves its settings

When you construct a chart without explicit calculation settings, it reads the current application configuration:

from ascendant import Ascendant

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    latitude=28.6139,
    longitude=77.2090,
    utc="+5:30",
)

The effective precedence is:

1. Explicit Ascendant(...) arguments
2. The current value installed by configure()
3. AscendantConfig() defaults

An existing instance keeps the resolved values stored in its horoscope_data. Later calls to configure() affect only instances created after the replacement.

Override one instance

The Ascendant constructor accepts enum members:

from ascendant import Ascendant, Ayanamsa, HouseSystem

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    latitude=28.6139,
    longitude=77.2090,
    utc="+5:30",
    ayanamsa=Ayanamsa.KRISHNAMURTI,
    house_system=HouseSystem.PLACIDUS,
)

It also accepts supported strings at this constructor boundary:

astro = Ascendant(
    year=1990,
    month=1,
    day=1,
    hour=12,
    minute=0,
    second=0,
    latitude=28.6139,
    longitude=77.2090,
    utc="+5:30",
    ayanamsa="raman",
    house_system="equal_2",
)

Ayanamsa strings are matched case-insensitively against their exact values. House-system strings are stripped, underscores become spaces, and comparison is case-insensitive. For example, "equal_2" resolves to HouseSystem.EQUAL_2. Unsupported strings raise ValueError while the instance is being constructed.

Ayanamsa

HouseSystem

Ascendant maps these enums to Swiss Ephemeris in horoscope.py. Swiss Ephemeris documents its sidereal modes and house methods.

Current chart-output boundary

The selected house-system code is used when Swiss Ephemeris calculates cusps and angles. The current public get_chart() result still places one complete sign in each numbered house from the rising sign and does not expose cusp longitudes. In this release, a non-Whole-Sign setting changes the underlying cusp calculation but not public get_chart() planet-to-house membership.

Reproducibility

Store the resolved enum values with the birth timezone, coordinates, and software version. When comparing two results, confirm those values before investigating a difference in the calculated chart.