Block Operations¶

Insert, export, query, and manage blocks and their attributes in your drawings.

Listing User-Defined Blocks¶

Retrieve all user-defined block names in the current drawing (excludes layout blocks and internal blocks starting with *).

blocks = cad.get_user_defined_blocks()
print(blocks)  # ['DoorBlock', 'WindowBlock', 'TitleBlock']

Inserting Blocks¶

From Current Drawing¶

Insert a block that already exists in the drawing's block table.

from AutoCAD import APoint, BlockReference

block = BlockReference(
    name="DoorBlock",
    insertion_point=APoint(10, 10, 0),
    scale=1.0,
    rotation=0.0
)
block_ref = cad.insert_block(block)

From External File¶

Insert a block from an external .dwg file into the current drawing.

block_ref = cad.insert_block_from_file(
    file_path=r"C:\Blocks\MyBlock.dwg",
    insertion_point=APoint(50, 50, 0),
    scale=2.0,
    rotation=0.0
)

Parameters:

Parameter	Type	Description
`file_path`	`str`	Path to the `.dwg` file containing the block definition
`insertion_point`	`APoint`	The point where the block will be inserted
`scale`	`float`	Scale factor (default: `1.0`)
`rotation`	`float`	Rotation angle in radians (default: `0.0`)

Exporting Blocks¶

Export one or more block definitions from the current drawing to a .dwg file.

cad.export_blocks_to_file(
    block_names=["DoorBlock", "WindowBlock"],
    file_path=r"C:\Exports\exported_blocks.dwg"
)

If the target file already exists, the blocks are merged into it. If it doesn't exist, a new file is created.

Note

This method temporarily inserts block instances at a safe far-away point, exports them via Wblock, then cleans up. The source drawing is closed without saving after export.

Querying Block Information¶

Get Block Extents¶

Get the bounding box (minimum and maximum points) of a block reference.

min_pt, max_pt = cad.get_block_extents("DoorBlock")
print(f"Min: {min_pt}, Max: {max_pt}")

Get Block Coordinates¶

Get the insertion points of all references of a specific block in the drawing.

coordinates = cad.get_block_coordinates("DoorBlock")
for pt in coordinates:
    print(f"Block at: ({pt.x}, {pt.y}, {pt.z})")

Repeating Blocks¶

Fill a horizontal span by repeating a block at regular intervals.

cad.repeat_block_horizontally(
    block_name="BrickBlock",
    total_length=100.0,
    block_length=10.0,
    insertion_point=APoint(0, 0, 0)
)
# Inserts 10 copies of "BrickBlock" side by side

Parameters:

Parameter	Type	Description
`block_name`	`str`	Name of the block to repeat
`total_length`	`float`	Total length to fill
`block_length`	`float`	Length of a single block
`insertion_point`	`APoint`	Starting insertion point

Block Attributes¶

Modify an Attribute¶

Change the value of a specific attribute by its tag.

# Get a block reference (e.g., from iterating model space)
for entity in cad.iter_objects("AcDbBlockReference"):
    if entity.Name == "TitleBlock":
        cad.modify_block_attribute(entity, "TITLE", "New Drawing Title")
        cad.modify_block_attribute(entity, "AUTHOR", "Jones Peter")

Modify Attribute by Old Value¶

Only update an attribute if its current value matches an expected value.

cad.modify_block_attribute_by_old_value(
    block_ref=entity,
    tag="STATUS",
    old_value="DRAFT",
    new_value="FINAL"
)

This is useful for conditional updates — the attribute is only changed if it currently holds old_value.

Delete an Attribute¶

Remove an attribute from a block reference by its tag.

cad.delete_block_attribute(entity, "OBSOLETE_TAG")

Complete Example¶

from AutoCAD import AutoCAD, APoint, BlockReference

cad = AutoCAD()

# List all blocks in the drawing
blocks = cad.get_user_defined_blocks()
print(f"Found blocks: {blocks}")

# Insert a block
block_ref = cad.insert_block(
    BlockReference("TitleBlock", APoint(0, 0, 0), scale=1.0, rotation=0.0)
)

# Set attributes on the inserted block
cad.modify_block_attribute(block_ref, "TITLE", "Floor Plan - Level 1")
cad.modify_block_attribute(block_ref, "DATE", "2026-03-14")

# Find all instances of a block
coords = cad.get_block_coordinates("DoorBlock")
print(f"Found {len(coords)} door blocks")

# Get bounding box of a block
min_pt, max_pt = cad.get_block_extents("DoorBlock")
width = max_pt.x - min_pt.x
height = max_pt.y - min_pt.y
print(f"Door block size: {width} x {height}")

# Insert a block from an external file
cad.insert_block_from_file(
    r"C:\Blocks\FurnitureBlock.dwg",
    APoint(20, 30, 0),
    scale=1.5
)

# Export blocks to a separate file
cad.export_blocks_to_file(
    ["TitleBlock", "DoorBlock"],
    r"C:\Exports\project_blocks.dwg"
)

cad.save()

API Reference¶

Method	Description
`get_user_defined_blocks()`	List all user-defined block names
`insert_block(block)`	Insert a block from the block table
`insert_block_from_file(file_path, insertion_point, scale, rotation)`	Insert a block from an external `.dwg` file
`export_blocks_to_file(block_names, file_path)`	Export blocks to a `.dwg` file
`get_block_extents(block_name)`	Get bounding box of a block reference
`get_block_coordinates(block_name)`	Get insertion points of all block references
`repeat_block_horizontally(block_name, total_length, block_length, insertion_point)`	Repeat a block to fill a length
`modify_block_attribute(block_ref, tag, new_value)`	Modify an attribute value
`modify_block_attribute_by_old_value(block_ref, tag, old_value, new_value)`	Conditionally modify an attribute
`delete_block_attribute(block_ref, tag)`	Delete an attribute from a block