fhirpathpy

library2.2.0pypypi✓ verified 88d ago

A Python implementation of the FHIRPath specification (FHIR R4), version 2.2.0, released Feb 2024. Follows minor version bumps when the upstream FHIRPath spec changes; patch releases fix bugs. Fully typed, supports evaluating expressions against FHIR resources represented as dicts or Pydantic models.

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pip install fhirpathpy

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INSTALL

IMPORT

SIG · FHIRPATHPY

fhirpathpy

analyticspythonv2.2.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

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

evaluate

✓ from fhirpathpy import evaluate

✗ from fhirpath import evaluate

Old package name `fhirpath` was deprecated; new import is `fhirpathpy`

Evaluates a FHIRPath expression against a FHIR resource (dict) and returns a list of values.

from fhirpathpy import evaluate resource = { "resourceType": "Patient", "name": [{"family": "Doe", "given": ["John"]}], "birthDate": "1970-01-01" } # Evaluate FHIRPath expression result = evaluate(resource, "Patient.name.family") print(result) # Output: ['Doe']

Debug

Known issues

breakingIn version 2.0+, the `evaluate` function returns a list of matching nodes (each a dict with `value`, `path`, etc.) instead of raw values. Use the `result` fixture to get the 'value' field if you need the scalar.

fix

Extract values with `[match['value'] for match in result]` or use the `value` property.

affects: >=2.0.0

breakingThe `fhirpathpy.parse` function was removed in v2.0. Use `evaluate` directly.

fix

Replace `parse(fhirpath_expr).evaluate(resource)` with `evaluate(resource, expr)`.

affects: >=2.0.0

deprecatedThe `fhirpathpy` package no longer supports Python 3.9 and earlier (requires >=3.10).

fix

Upgrade Python to 3.10 or later, or pin to fhirpathpy<2.2.0 if you must stay on older Python.

affects: >=2.2.0

gotchaThe library does not support custom functions or extensions to the FHIRPath spec. If you need extensions, you must pre/post-process.

fix

Wrap the query with additional Python logic before/after evaluate() to inject custom behavior.

affects: all

Errors

Common errors & fixes

AttributeError: module 'fhirpath' has no attribute 'evaluate'

Importing the wrong package name (fhirpath instead of fhirpathpy).

fix

Install `pip install fhirpathpy` and import as `from fhirpathpy import evaluate`.

fhirpathpy.exceptions.EvaluationException: Unknown function: myCustomFunc

Trying to call a custom function not defined in the FHIRPath spec or in fhirpathpy's built-ins.

fix

Remove custom functions or implement them as Python helpers before/after evaluate().

TypeError: Object of type Patient is not JSON serializable

Passing a Pydantic model object directly instead of a dict.

fix

Use `.model_dump()` (Pydantic v2) or `.dict()` (Pydantic v1) to convert to dict before calling evaluate().

Upgrade

Version history

2.2.0latest on PyPI · released Apr 16, 2026

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Dependencies

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Agent activity

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Resources

githubhttps://github.com/beda-software/fhirpath-py.git ↗

homepagehttps://github.com/beda-software/fhirpath-py.git ↗