JSON Logic Qubit Python Parser

0.9.1 · maintenance · verified Wed Apr 15

json-logic-qubit is a Python parser that accepts JsonLogic rules and executes them. It is a port of the JavaScript json-logic-js project, designed to allow sharing rules (logic) between front-end and back-end code, and for storing logic in databases. The current version is 0.9.1. The project appears to be in maintenance mode with infrequent updates.

Warnings

deprecated The json-logic-qubit library has not been updated since August 2018. While functional, it may lack compatibility with newer Python versions or not include features/bug fixes from the broader JsonLogic ecosystem. Related projects by 'QubitProducts' have been archived.
Fix: Thoroughly test with your specific Python environment and consider alternative actively maintained JsonLogic implementations if long-term support or cutting-edge features are required.
gotcha An older, less maintained Python package named `json-logic` exists on PyPI. Installing it by mistake can lead to an outdated and buggy implementation of the JsonLogic specification.
Fix: Always use `pip install json-logic-qubit` to ensure you get this fork, which was created to address maintenance issues of the original `json-logic` package. Verify your `from json_logic import jsonLogic` import works as expected.
gotcha Older versions of a base `json-logic` library (from which this project is forked) experienced `TypeError: 'dict_keys' object does not support indexing` with Python 3.6+. While potentially fixed in this fork, due to the project's age, unforeseen compatibility issues with modern Python versions (3.7+) may arise.
Fix: Test your rules and data extensively on your target Python version. Inspect error messages for issues related to dictionary views or iteration changes in newer Python versions.
gotcha Some JsonLogic implementations (in other languages) have had a known issue where the `{"var": "key"}` operator returns `None` instead of `False` when the referenced data value is literally `False`. This can break logic relying on explicit boolean `False` checks.
Fix: Rigorously test rules that involve `var` operators with boolean `False` values to ensure the expected output. Consider explicit comparisons like `{"==": [{"var": "key"}, false]}` if ambiguity arises.

Install

pip install json-logic-qubit Install latest version

Imports

jsonLogic
wrong:
```
from json_logic_qubit import jsonLogic
```
correct:
```
from json_logic import jsonLogic
```
The primary function `jsonLogic` is exposed directly from the `json_logic` sub-package, not the top-level `json_logic_qubit`.

Quickstart

This quickstart demonstrates how to import and use the `jsonLogic` function with both a simple comparison rule and a more complex, data-driven rule that checks nested properties.

from json_logic import jsonLogic

# Simple rule: 1 == 1
result1 = jsonLogic({ "==" : [1, 1] })
print(f"Simple rule (1 == 1): {result1}")

# Data-driven rule: check if 'temp' < 110 AND 'pie.filling' == 'apple'
rules = {
    "and" : [
        { "<" : [ { "var" : "temp" }, 110 ] },
        { "==" : [ { "var" : "pie.filling" }, "apple" ] }
    ]
}
data = { "temp" : 100, "pie" : { "filling" : "apple" } }

result2 = jsonLogic(rules, data)
print(f"Complex rule (pie ready): {result2}")

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