janaf

library1.2.1pypypi✓ verified 82d ago

janaf is a Python wrapper for the NIST-JANAF Thermochemical Tables, providing programmatic access to thermodynamic data for various chemical species. The current version is 1.2.1, with releases occurring a few times a year, often including dependency updates and minor feature enhancements.

data http-networking

pip install janaf

github ↗package ↗

INSTALL

IMPORT

SIG · JANAF

janaf

datapythonv1.2.1

Install

7.8s avg

Import

—

Disk

389MB

Pass rate

9/ 10

Env Coverage9 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.2.1 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

✓ —

✓ 7.88s

py 3.11

✓ —

✓ 7.53s

py 3.12

✓ —

✓ 7.53s

py 3.13

✓ —

✓ 7.6s

py 3.9

✕ build_error

✓ 8.45s

389MB installed

● package 389MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Table

✓ from janaf import Table

✗ from janaf import get_table

✓ from janaf import search

index

✓ from janaf import index

This quickstart demonstrates how to fetch thermochemical data for a species (e.g., H2O) using `janaf.get_table()` and access the data as a pandas DataFrame. It also shows how to retrieve specific property values.

from janaf import get_table # Get thermochemical data for Water water_table = get_table("H2O") # Access data as a pandas DataFrame print("\nWater Table (first 5 rows):\n", water_table.df.head()) # Access specific properties print(f"\nEnthalpy (H) at 298.15 K: {water_table.df.loc[298.15, 'H/RT']} RT") # Get data for another species oxygen_table = get_table("O2") print("\nOxygen Table (first 5 rows):\n", oxygen_table.df.head())

Debug

Known issues

breakingPython 3.8 support was dropped in `janaf` v1.2.1. If you are using Python 3.8 or older, you must either upgrade your Python version or pin `janaf` to a version older than 1.2.1.

fix

Upgrade Python to 3.9+ or use `pip install 'janaf<1.2.1'`.

affects: >=1.2.1

breakingAs of v1.1.0, `janaf` no longer performs runtime imputation of missing data points (e.g., for `cp0/R`). If your code relied on these estimated values for certain species or temperature ranges, you might now encounter `NaN` values where data was previously provided.

fix

Update your code to explicitly handle `NaN` values (e.g., `dropna()`, `fillna()`, or manual interpolation) or ensure your data sources cover the full range of interest. Alternatively, pin `janaf` to `<1.1.0` if this imputation behavior is critical.

affects: >=1.1.0

gotchaThe `Table.to_xarray()` method requires the optional `xarray` dependency to be installed. If `xarray` is not installed, calling this method will result in an `AttributeError`.

fix

Install `janaf` with the `xarray` extra: `pip install "janaf[xarray]"` or install `xarray` separately: `pip install xarray`.

affects: >=1.2.0

Upgrade

Version history

1.2.1latest on PyPI · released Feb 18, 2026

Audit

Dependencies

numpyrequiredCore dependency for numerical operations.

pandasrequiredCore dependency for data handling (DataFrames).

xarrayoptionalRequired for the Table.to_xarray() method.

Agent activity

15 hits · last 30 days

node

Resources

githubhttps://github.com/n-takumasa/py-janaf ↗

packagehttps://pypi.org/project/janaf/ ↗