Installation

Python and environment

hst123 requires Python 3.12 only (see requires-python in pyproject.toml: >=3.12,<3.13). The stack is validated with NumPy 1.x, Astropy 5.x, SciPy 1.x, and DrizzlePac; use the provided Conda environment when possible so binary wheels match.

Conda (recommended)

From the repository root:

conda env create -f environment.yml
conda activate hst123
pip install drizzlepac
pip install -e .

This installs the hst123 and hst123-install-dolphot console scripts.

`pip install` alone (without Conda)

Use a venv with Python 3.12, then pip install drizzlepac and pip install -e . from the repo. If NumPy/Astropy must build from source, prefer installing those from Conda first or match the pins in pyproject.toml.

STScI WCS (`stwcs`)

WCS utilities used for alignment (updatewcs, HSTWCS, altwcs) are bundled under hst123.utils.stwcs (see STWCS_VENDOR.txt). The package on PyPI named stwcs is not an hst123 dependency; DrizzlePac may install it for its own use. Application code should use hst123.utils.stsci_wcs.

DOLPHOT (optional)

DOLPHOT is not bundled. For --run-dolphot / --scrape-dolphot, install DOLPHOT with the helper after activating your environment:

conda activate hst123
hst123-install-dolphot

The helper downloads DOLPHOT 3.1 sources and PSF tables under $CONDA_PREFIX/opt/hst123-dolphot, runs make, and symlinks dolphot, calcsky, and related tools into $CONDA_PREFIX/bin. Masking (ACS/WFC3/WFPC2) and splitgroups use Python implementations by default (see hst123.utils.dolphot_mask, hst123.utils.dolphot_splitgroups); set HST123_DOLPHOT_MASK_EXTERNAL=1 or HST123_DOLPHOT_SPLITGROUPS_EXTERNAL=1 to force C binaries.

Without Conda, pass --dolphot-dir /path/to/dolphot to the installer or add DOLPHOT to PATH manually. See hst123-install-dolphot --help and the DOLPHOT website.

Documentation build

pip install -e ".[docs]"
cd docs && make html

Output is under docs/build/html/. The project also publishes docs to GitHub Pages via CI.