usfm3 0.1.9

Error-tolerant USFM 3.x parser

usfm3

usfm3 is a Python parser for USFM 3.x. It turns USFM into Python-friendly outputs:

• to_usj(spans=False): USJ as a dict
• to_usx(): USX as an XML str
• to_usfm(): normalized USFM as a str
• to_vref(): a verse-text map like {"GEN 1:1": "In the beginning..."}

The parser is error-tolerant, so malformed input still produces a parse result with structured diagnostics.

Built in Rust for speed, with native Python bindings via PyO3.

Installation

pip install usfm3

Requires Python 3.9+.

Quick Start

import usfm3

text = r"""\id GEN
\c 1
\p
\v 1 In the beginning God created the heavens and the earth.
"""

result = usfm3.parse(text)

print(result.to_vref()["GEN 1:1"])

for diagnostic in result.diagnostics:
    print(
        f"[{diagnostic.severity}] {diagnostic.code}: "
        f"{diagnostic.message} ({diagnostic.start}..{diagnostic.end})"
    )

usj = result.to_usj()
usj_with_spans = result.to_usj(spans=True)
usx = result.to_usx()
normalized_usfm = result.to_usfm()

Validation

parse() runs semantic validation by default, so diagnostics can include issues such as chapter and verse sequencing, invalid attributes, or mismatched milestones.

If you only want parsing, disable validation:

result = usfm3.parse(text, validate=False)

API Summary

usfm3.parse(usfm: str, validate: bool = True) -> ParseResult

Parses a USFM string and returns a ParseResult.

ParseResult

• to_usj(spans: bool = False) -> dict
• to_usx() -> str
• to_usfm() -> str
• to_vref() -> dict[str, str]
• has_errors() -> bool
• diagnostics -> list[Diagnostic]

Diagnostic

Each diagnostic has:

• severity: "error", "warning", or "info"
• code: machine-readable code such as "UnknownMarker"
• message: human-readable message
• start
• end

start and end are byte offsets into the original source.

Notes

• to_vref() returns plain verse text keyed by references such as "GEN 1:1".
• to_usfm() returns normalized USFM, so whitespace may be regularized.
• When spans=True, structural USJ nodes include a nested spans object with node and optional code, number, and close ranges.
• Invalid USFM is reported through diagnostics; parse() still returns a result.

Related Packages

• Rust crate: crates.io/crates/usfm3
• JavaScript/TypeScript package: npmjs.com/package/usfm3
• Source code: github.com/jcuenod/usfm3

License

MIT