Python, Extract Polyline Lengths with Associated Text Labels in AutoCAD

[Danielm103]

sample of this

 

import traceback
from pyrx import Db, Ed, Ge, Ap, Rx, Gs


@Ap.Command()
def doit():
    try:
        # select
        db = Db.curDb()
        filter = [(Db.DxfCode.kDxfStart, "TEXT,LWPOLYLINE")]
        ps, ss = Ed.Editor.select(filter)
        if ps != Ed.PromptStatus.eOk:
            raise RuntimeError("Selection Error! {}: ".format(ps))
        texts = [Db.Text(id) for id in ss.objectIds(Db.Text.desc())]
        plines = [Db.Polyline(id) for id in ss.objectIds(Db.Polyline.desc())]

        # make kdtree & list of points
        pntmap = {}
        plpoints = []
        for pl in plines:
            plpoints.append(pl.getStartPoint())
            plpoints.append(pl.getEndPoint())
            pntmap[pl.getStartPoint()] = pl
            pntmap[pl.getEndPoint()] = pl

        # search closest pline
        results = []
        tree = Ge.Point3dTree(plpoints)
        for text in texts:
            idxs, _ = tree.knnSearch(text.position(), 1)
            pl: Db.Polyline = pntmap[plpoints[idxs[0]]]
            results.append([text.textString(), pl.getDistAtParam(pl.getEndParam())])

        # format mtext
        results = sorted(results, key=lambda x: int(x[0][2:]))
        buffer = "{:<6}\t{}\\P".format("S.No", "Length Ft")
        buffer += "".join(f"{sno:<6}\t  {plen:>.2f}\\P" for sno, plen in results)

        # make mtext, add to currentSpace
        ps, pnt = Ed.Editor.getPoint("\nPick Text Position")
        mt = Db.MText()
        mt.setDatabaseDefaults(db)
        mt.setLocation(pnt)
        mt.setContents(buffer)
        cs = db.currentSpace(Db.OpenMode.kForWrite)
        cs.appendAcDbEntity(mt)

    except Exception as err:
        traceback.print_exception(err)

 

[BIGAL]

Would a table answer be perhaps neater than Mtext ? Just ask for text size for table.

Edited Saturday at 10:02 PM by BIGAL

[Danielm103]

Yep, easier too, since there would be not need to format the string for MText.

Even though Python has robust string operations, it’s still weird to get it perfect

https://docs.python.org/3/library/string.html

 

I was just following along the original sample. The part I wanted to illustrate was, using a hashmap for mapping points to objects, and using the KD-Tree to do the spatial search 

 

I wrote the same KD-Tree and map for AutoLISP, I’m just really bad at lisp, so it’s hard for me to make samples lol

https://github.com/CEXT-Dan/ads_geo

 

  

 

[BIGAL]

Just a comment done  a lot of find object next to text, just used get text insertion point, then use "ssget "F" pts" the pts are say 10 points made via a polar defun looking like a circle . I noticed you go the other way around looking around the pline for the text.

 

Would be good to get a true sample dwg.

Edited Saturday at 10:25 PM by BIGAL

[Danielm103]

Yeah, I chose to search for the closest polyline to the text. BricsCAD has ssget crossing circle , (ssget "CC" point1 point2), could be similar to a radius search. Caveat, you’d have to call ssget for every mtext

 

 

There’s a .DWG in the original post in the lisp forums

[Danielm103]

I used a similar approach here, the user wanted to set the elevation of the contour lines to the nearest label.  This is where KD-Trees really start to shine as they can handle millions of points, with millions of searches

 

 

[Tamim]

On 25/10/2025 at 15:29, Danielm103 said:

sample of this

 

import traceback
from pyrx import Db, Ed, Ge, Ap, Rx, Gs


@Ap.Command()
def doit():
    try:
        # select
        db = Db.curDb()
        filter = [(Db.DxfCode.kDxfStart, "TEXT,LWPOLYLINE")]
        ps, ss = Ed.Editor.select(filter)
        if ps != Ed.PromptStatus.eOk:
            raise RuntimeError("Selection Error! {}: ".format(ps))
        texts = [Db.Text(id) for id in ss.objectIds(Db.Text.desc())]
        plines = [Db.Polyline(id) for id in ss.objectIds(Db.Polyline.desc())]

        # make kdtree & list of points
        pntmap = {}
        plpoints = []
        for pl in plines:
            plpoints.append(pl.getStartPoint())
            plpoints.append(pl.getEndPoint())
            pntmap[pl.getStartPoint()] = pl
            pntmap[pl.getEndPoint()] = pl

        # search closest pline
        results = []
        tree = Ge.Point3dTree(plpoints)
        for text in texts:
            idxs, _ = tree.knnSearch(text.position(), 1)
            pl: Db.Polyline = pntmap[plpoints[idxs[0]]]
            results.append([text.textString(), pl.getDistAtParam(pl.getEndParam())])

        # format mtext
        results = sorted(results, key=lambda x: int(x[0][2:]))
        buffer = "{:<6}\t{}\\P".format("S.No", "Length Ft")
        buffer += "".join(f"{sno:<6}\t  {plen:>.2f}\\P" for sno, plen in results)

        # make mtext, add to currentSpace
        ps, pnt = Ed.Editor.getPoint("\nPick Text Position")
        mt = Db.MText()
        mt.setDatabaseDefaults(db)
        mt.setLocation(pnt)
        mt.setContents(buffer)
        cs = db.currentSpace(Db.OpenMode.kForWrite)
        cs.appendAcDbEntity(mt)

    except Exception as err:
        traceback.print_exception(err)

 

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