Detection

License detection for one installed distribution — declared metadata first, a bundled-license-file text-matching fallback second. See How detection works for the full priority order and rationale.

trustedlicenses.DistributionLicence(name, keys, categories, source, suggested=frozenset(), version='') dataclass

The licenses detected for one installed distribution.

Attributes:

Name	Type	Description
name	str	Canonical (PEP 503 normalised) distribution name.
keys	frozenset[str]	SPDX license identifiers detected for the distribution (e.g. "MIT", "Apache-2.0").
categories	frozenset[str]	Categories of keys.
source	str	Where the detection came from, for a failure report.
suggested	frozenset[tuple[str, str]]	(declared statement, corrected SPDX id) pairs :func:_correct_license_statement produced for this distribution's declared statements. Populated whenever keys came back empty, regardless of whether anything ends up trusting it -- purely informational at this layer; see the module docstring.
version	str	The installed version, so a later, opt-in index check knows what "newer" means. Empty when unknown.

trustedlicenses.canonical_name(raw)

Normalise a distribution name per PEP 503.

Parameters:

Name	Type	Description	Default
raw	str	Distribution name as written in metadata or configuration.	required

Returns:

Type	Description
str	The lower-cased name with runs of -, _ and . collapsed to -.

Source code in src/trustedlicenses/detection.py

def canonical_name(raw: str) -> str:
    """Normalise a distribution name per PEP 503.

    Args:
        raw: Distribution name as written in metadata or configuration.

    Returns:
        The lower-cased name with runs of ``-``, ``_`` and ``.`` collapsed to ``-``.
    """
    return raw.strip().lower().replace("_", "-").replace(".", "-")

trustedlicenses.inspect_distribution(dist, name=None)

Detect the licenses of one installed distribution.

Parameters:

Name	Type	Description	Default
dist	Distribution	The installed distribution.	required
name	str | None	Its canonical name. Computed from dist's own metadata when omitted.	None

Returns:

Type	Description
DistributionLicence	What was detected, and where it was detected from.

Source code in src/trustedlicenses/detection.py

def inspect_distribution(dist: Distribution, name: str | None = None) -> DistributionLicence:
    """Detect the licenses of one installed distribution.

    Args:
        dist: The installed distribution.
        name: Its canonical name. Computed from ``dist``'s own metadata when omitted.

    Returns:
        What was detected, and where it was detected from.
    """
    resolved_name = name or canonical_name(dist.metadata["Name"] or "")

    statements = _declared_statements(dist)
    declared_keys = _keys_from_declared(statements)
    if declared_keys:
        return DistributionLicence(
            name=resolved_name,
            keys=frozenset(declared_keys),
            categories=frozenset(_categories(declared_keys)),
            source="declared metadata",
            version=dist.version,
        )

    suggested = _suggested_corrections(statements)

    files = _licence_files(_dist_info_dir(dist))
    if files:
        keys = _keys_from_licence_files(files)
        source = "license files: " + ", ".join(sorted({path.name for path in files}))
    else:
        keys = set()
        source = "no license information found"
    return DistributionLicence(
        name=resolved_name,
        keys=frozenset(keys),
        categories=frozenset(_categories(keys)),
        source=source,
        suggested=suggested,
        version=dist.version,
    )

trustedlicenses.inspect_installed(name)

Detect the licenses of an installed distribution by name.

Parameters:

Name	Type	Description	Default
name	str	The distribution's project name, as installed (any case/separator).	required

Returns:

Type	Description
DistributionLicence	What was detected, and where it was detected from.

Raises:

Type	Description
PackageNotFoundError	No such distribution is installed.

Source code in src/trustedlicenses/detection.py

def inspect_installed(name: str) -> DistributionLicence:
    """Detect the licenses of an installed distribution by name.

    Args:
        name: The distribution's project name, as installed (any case/separator).

    Returns:
        What was detected, and where it was detected from.

    Raises:
        importlib.metadata.PackageNotFoundError: No such distribution is installed.
    """
    return inspect_distribution(distribution(name), name=canonical_name(name))