API Reference

LS-DYNA Keywords Reader Library

class dynakw.DynaKeywordReader(filename: str, follow_include: bool = False, debug: bool = False)

Main class for reading and writing LS-DYNA keyword files

Initializes the LSDynaKeyword object.

Parameters:

• filename (str) – The path to the LS-DYNA file.

• follow_include (bool) – Read include files.

• debug (bool) – Whether to print debug statements.

find_keywords(keyword_type: KeywordType) → List[LSDynaKeyword]

Find all keywords of a specific type

keywords() → Iterator[LSDynaKeyword]

Iterator over keywords, reading from the file as needed.

parameters() → Dict[str, float | int | str]

Returns a dictionary of parameter names and values found in the file.

set_parameters(params_update_dict: Dict[str, float | int | str])

Updates parameters in the file based on the dictionary.

Parameters:

params_update_dict (dict) – Dictionary where keys are parameter names (str) and values are the new values (float, int, str). Keys are matched case-insensitively.

write(filename: str)

Write all keywords to a file

class dynakw.KeywordType(*values)

Enumeration of supported LS-DYNA keywords

class dynakw.LSDynaKeyword(keyword_name: str, raw_lines: List[str] = None, start_line: int = None)

Base class for all LS-DYNA keyword objects.

This class provides the basic structure for representing an LS-DYNA keyword, including methods for parsing from raw text and writing back to a file format.

Subclasses can either: - Define card_schemas (a list of CardSchema objects) to get automatic

parse and write behaviour provided by this base class, or

• Override _parse_raw_data and write directly for custom logic.

cards

The cards content as described in the LS-DYNA manual; e.g. kw.cards[‘Card 1’][‘SF’]

Type:

Dict[str, Dict[str, np.ndarray]] = {}

card_schemas

Declarative card layout. When set, the base class automatically handles parsing and writing.

Type:

List[CardSchema]

Initializes the LSDynaKeyword object.

Parameters:

• keyword_name (str) – The full name of the keyword (e.g., “*BOUNDARY_PRESCRIBED_MOTION_NODE”).

• raw_lines (List[str], optional) – The raw text lines for the keyword. Defaults to None.

• start_line (int, optional) – The line number where the keyword starts in the file. Defaults to None.

KEYWORD_MAP: Dict[str, LSDynaKeyword] = {'*BOUNDARY_PRESCRIBED_MOTION': <class 'dynakw.keywords.BOUNDARY_PRESCRIBED_MOTION.BoundaryPrescribedMotion'>, '*ELEMENT_SHELL': <class 'dynakw.keywords.ELEMENT_SHELL.ElementShell'>, '*ELEMENT_SOLID': <class 'dynakw.keywords.ELEMENT_SOLID.ElementSolid'>, '*MAT_001': <class 'dynakw.keywords.MAT_ELASTIC.MatElastic'>, '*MAT_001_FLUID': <class 'dynakw.keywords.MAT_ELASTIC.MatElastic'>, '*MAT_ELASTIC': <class 'dynakw.keywords.MAT_ELASTIC.MatElastic'>, '*MAT_ELASTIC_FLUID': <class 'dynakw.keywords.MAT_ELASTIC.MatElastic'>, '*NODE': <class 'dynakw.keywords.NODE.Node'>, '*PARAMETER': <class 'dynakw.keywords.PARAMETER.Parameter'>, '*PARAMETER_EXPRESSION': <class 'dynakw.keywords.PARAMETER_EXPRESSION.ParameterExpression'>, '*PART': <class 'dynakw.keywords.PART.Part'>, '*SECTION_SHELL': <class 'dynakw.keywords.SECTION_SHELL.SectionShell'>, '*SECTION_SOLID': <class 'dynakw.keywords.SECTION_SOLID.SectionSolid'>, '*UNKNOWN': <class 'dynakw.keywords.UNKNOWN.Unknown'>}

A registry of all known keyword strings and the classes that handle them.

card_groups: List[CardGroup] = []

Grouped card layout for interleaved (per-element) parse/write. When set, each group is written as: all headers first, then one row per schema per element. Takes precedence over card_schemas in the default implementations.

card_schemas: List[CardSchema] = []

Declarative card layout. Override in subclasses to enable auto-parse/write.

static discover_keywords()

Dynamically imports all keyword modules from the ‘keywords’ directory to ensure they are registered in the KEYWORD_MAP.

write(file_obj: TextIO)

Writes the keyword and its data to a file object.

If card_groups is defined, uses interleaved grouped writing. If card_schemas is defined, uses sequential schema writing. Otherwise subclasses must override this method.

class dynakw.ParameterRef(name: str)

A reference to a *PARAMETER variable in a data field.

In LS-DYNA files, parameter references appear as &VARNAME inside numeric or string card fields. Instead of attempting (and failing) to convert the field to int or float, the parser stores a ParameterRef object so that the reference is preserved faithfully on round-trip.

Example:

*MAT_ELASTIC
$      MID        RO         E        PR
         1     7.85e-9    &Emod    &PRval

After parsing, kw.cards['Card 1']['E'][0] is ParameterRef('Emod') rather than raising a ValueError.

name: str

Variable name without the leading &.