Classes Section

The CLASSES section in DXF files holds the information for application-defined classes whose instances appear in Layout objects. As usual package user there is no need to bother about CLASSES.

See also

DXF Internals: CLASSES Section

class ezdxf.sections.classes.ClassesSection

Storage of all DXFClass objects, they are not stored in the entities database, because CLASS instances do not have a handle attribute.

add_class(name: str)

Register a known class by name.

get(name: str) → ezdxf.entities.dxfclass.DXFClass

Returns the first class matching name.

Storage key is the (name, cpp_class_name) tuple, because there are some classes with the same name but different cpp_class_names.

add_required_classes(dxfversion: str) → None

Add all required CLASS definitions for the specified DXF version.

update_instance_counters() → None

Update CLASS instance counter for all registered classes, requires DXF R2004+.

class ezdxf.entities.DXFClass

Information about application-defined classes.

Class DXF record name.


C++ class name. Used to bind with software that defines object class behavior.


Application name. Posted in Alert box when a class definition listed in this section is not currently loaded.


Proxy capabilities flag

0 No operations allowed (0)
1 Erase allowed (0x1)
2 Transform allowed (0x2)
4 Color change allowed (0x4)
8 Layer change allowed (0x8)
16 Linetype change allowed (0x10)
32 Linetype scale change allowed (0x20)
64 Visibility change allowed (0x40)
128 Cloning allowed (0x80)
256 Lineweight change allowed (0x100)
512 Plot Style Name change allowed (0x200)
895 All operations except cloning allowed (0x37F)
1023 All operations allowed (0x3FF)
1024 Disables proxy warning dialog (0x400)
32768 R13 format proxy (0x8000)

Instance count for a custom class.


Set to 1 if class was not loaded when this DXF file was created, and 0 otherwise.


Set to 1 if class was derived from the DXFGraphic class and can reside in layouts. If 0, instances may appear only in the OBJECTS section.


Unique name as (name, cpp_class_name) tuple.