format_spectrum_id

emmet.core.xas.format_spectrum_id(spectrum_id, legacy, prefix='mp', padlen=ID_PADLEN)

Render an XAS spectrum id in either legacy or new alpha form.

Spectrum ids are composite identifiers built at runtime from a task id plus three typed suffix components (spectrum type, absorbing element, edge), all joined with -. Their shape convention follows the same prefix-dropping rule as task ids — the leading id portion is prefixed in legacy form and bare in alpha form:

  • Legacy form: mp-<int>-<XasType>-<Element>-<XasEdge> (e.g. mp-779827-XANES-O-K).

  • New alpha form: <padded-alpha>-<XasType>-<Element>-<XasEdge> (e.g. aaabsjpj-XANES-O-K) with no mp- prefix.

Parsing delegates to validate_xas_spectrum_id() (and through it to validate_compound_identifier()), so the suffix shape stays in lockstep with the canonical XAS spectrum_id schema.

Args:
spectrum_id: A spectrum id in either form. May be the bare composite

string, or anything validate_xas_spectrum_id() accepts.

legacy: If True, returns the legacy mp-<int>-... form. If False,

returns the bare-alpha-prefixed <padded-alpha>-... form.

prefix: The id prefix used in the legacy form. Defaults to "mp". padlen: The minimum identifier length on the alpha-form output.

Defaults to 8.

Returns:

The formatted string. If spectrum_id is None or empty, it is returned unchanged. If parsing fails, the input is coerced to a string and returned unchanged (defensive: this helper never raises from a display path).

Examples:
>>> format_spectrum_id("mp-779827-XANES-O-K", legacy=False)
'aaabsjpj-XANES-O-K'
>>> format_spectrum_id("aaabsjpj-XANES-O-K", legacy=True)
'mp-779827-XANES-O-K'
Return type:

str | None

Parameters:

  • spectrum_id (Any)

  • legacy (bool)

  • prefix (str)

  • padlen (int)