See also

For usage of the query features see the tutorial: Tutorial for getting data from DXF files

Entity Query String

QueryString := EntityQuery ("[" AttribQuery "]" "i"?)*

The query string is the combination of two queries, first the required entity query and second the optional attribute query, enclosed in square brackets, append 'i' after the closing square bracket to ignore case for strings.

Entity Query

The entity query is a whitespace separated list of DXF entity names or the special name '*'. Where '*' means all DXF entities, exclude some entity types by appending their names with a preceding ! (e.g. all entities except LINE = '* !LINE'). All DXF names have to be uppercase.

Attribute Query

The optional attribute query is a boolean expression, supported operators are:

  • not (!): !term is true, if term is false

  • and (&): term & term is true, if both terms are true

  • or (|): term | term is true, if one term is true

  • and arbitrary nested round brackets

  • append (i) after the closing square bracket to ignore case for strings

Attribute selection is a term: “name comparator value”, where name is a DXF entity attribute in lowercase, value is a integer, float or double quoted string, valid comparators are:

  • "==" equal “value”

  • "!=" not equal “value”

  • "<" lower than “value”

  • "<=" lower or equal than “value”

  • ">" greater than “value”

  • ">=" greater or equal than “value”

  • "?" match regular expression “value”

  • "!?" does not match regular expression “value”

Query Result

The EntityQuery class is the return type of all query() methods. EntityQuery contains all DXF entities of the source collection, which matches one name of the entity query AND the whole attribute query. If a DXF entity does not have or support a required attribute, the corresponding attribute search term is False.

examples:

  • LINE[text ? ".*"]: always empty, because the LINE entity has no text attribute.

  • LINE CIRCLE[layer=="construction"]: all LINE and CIRCLE entities with layer == "construction"

  • *[!(layer=="construction" & color<7)]: all entities except those with layer == "construction" and color < 7

  • *[layer=="construction"]i, (ignore case) all entities with layer == "construction" | "Construction" | "ConStruction"

EntityQuery Class

class ezdxf.query.EntityQuery

The EntityQuery class is a result container, which is filled with dxf entities matching the query string. It is possible to add entities to the container (extend), remove entities from the container and to filter the container. Supports the standard Python Sequence methods and protocols.

first

First entity or None.

last

Last entity or None.

__len__() → int

Returns count of DXF entities.

__getitem__(item: int) → DXFEntity

Returns DXFEntity at index item, supports negative indices and slicing.

__iter__() → Iterable[DXFEntity]

Returns iterable of DXFEntity objects.

extend(entities: Iterable[DXFEntity], query: str = '*', unique: bool = True) → EntityQuery

Extent the EntityQuery container by entities matching an additional query.

remove(query: str = '*') → None

Remove all entities from EntityQuery container matching this additional query.

query(query: str = '*') → ezdxf.query.EntityQuery

Returns a new EntityQuery container with all entities matching this additional query.

raises: ParseException (pyparsing.py)

groupby(dxfattrib: str = '', key: Callable[[DXFEntity], Hashable] = None) → Dict[Hashable, List[DXFEntity]]

Returns a dict of entity lists, where entities are grouped by a DXF attribute or a key function.

Parameters
  • dxfattrib – grouping DXF attribute as string like 'layer'

  • key – key function, which accepts a DXFEntity as argument, returns grouping key of this entity or None for ignore this object. Reason for ignoring: a queried DXF attribute is not supported by this entity

The new() Function

ezdxf.query.new(entities: Iterable['DXFEntity'] = None, query: str = '*') → EntityQuery

Start a new query based on sequence entities. The entities argument has to be an iterable of DXFEntity or inherited objects and returns an EntityQuery object.