Inline Python REPL

[schoeller]

Dear all,

thanks for OCS.
I have tried to assemble an inline Python REPL plugin extending the existing API for V3. I find Python scripting in CAD very useful. Changes to src/ have been made. It uses the locally installed Python interpreter, so pypi.org is available. The workflow is as follows:

1. Start OCS and from NEW document launch PYTHONSHELL.
2. This opens prefereably the zed editor attached to main.py in a temporary directory.
3. Edit the script an run from the editor.

Interprocess-communication is maintained to protect the host. For performance a serde + bincode bridge is opened. Below script generates 100000 points in OCS and deletes.

import ocs
import random
import time

# Starter script for the OpenCAD Studio Python REPL.
# Use ocs.doc to read and modify the host document.

print("OpenCAD Studio Python REPL ready.")
print(f"Entities: {len(ocs.doc.entities)}")
print(f"Snapshot version: {ocs.doc.version}")

def roundtrip_100000_points():
    random.seed(42)
    pts = [(random.uniform(0, 100000), random.uniform(0, 100000), 0.0) for _ in range(100000)]

    t0 = time.perf_counter()
    ocs.doc.add_many(ocs.Point(x, y, z, layer="PTS") for x, y, z in pts)
    ocs.doc.commit()
    t1 = time.perf_counter()
    add_time = t1 - t0

    assert len(ocs.doc.entities) == 100000, f"expected 100000 points, got {len(ocs.doc.entities)}"

    t0 = time.perf_counter()
    ocs.doc.remove_all()
    ocs.doc.commit()
    t1 = time.perf_counter()
    remove_time = t1 - t0

    assert len(ocs.doc.entities) == 0, f"expected 0 points, got {len(ocs.doc.entities)}"
    return add_time, remove_time

if __name__ == "__main__":
    add_time, remove_time = roundtrip_100000_points()
    print(f"add 100000 points: {add_time:.3f}s")
    print(f"remove 100000 points: {remove_time:.3f}s")
    assert add_time + remove_time < 3.0, "roundtrip too slow"

print(f"Entities: {len(ocs.doc.entities)}")
print(f"Snapshot version: {ocs.doc.version}")

On my laptop this outputs, meaning roughly 2s for add/remove 100000 points:

OpenCAD Studio Python REPL ready.
Entities: 100000
Snapshot version: 4
add 100000 points: 1.324s
remove 100000 points: 0.878s
Entities: 0
Snapshot version: 7

Please find attached screencast for further details. Before continuing forward to a pull request I prefer a discussion whether this is considered a reasonable addition or simply overshot and not priority.

Best

Seb

REPL.mp4

Update: swapped video

[HakanSeven12]

In video nothing shown on the screen. Maybe you need to try another object type to demonstrate :) Also if you want it we can add it to plugin store

[subhasish20]

I couldn't see anything on the screen in the video. Maybe using a different object type would better demonstrate the feature. 🙂 We can also publish it to the plugin store if that sounds good."

[schoeller]

Started over based on API V2 after commit b7dc62f. Results have been pushed to ocs_python_repl. Usage is trouble some since current API does not do async. So after execution from editor PYTHONUPDATE has to be called manually. Am stitching up a V4 proposal for async extension and will bring forward whenever ready.