7. Remote control: Jupyter, scripts, Excel, C#

Besides the editor, SwPy can be driven from outside SOLIDWORKS. The code you send still runs inside SOLIDWORKS (fast, with sw, doc, model, units and packages), and results come back to the caller.

From any Python (Jupyter, VS Code, scripts)

The client needs only pywin32 (pip install pywin32) and the swpy package folder on sys.path (the python folder of the SwPy installation, e.g. sys.path.append(r"...\SwPy\python")).

import swpy.client as swc

sw = swc.connect()                        # attach to the running SOLIDWORKS, load SwPy if needed
sw.eval("doc.GetTitle()")                 # -> 'Part1'
sw.eval("model.mass['volume']")           # -> 0.00012  (real Python float)
sw.exec("model.dims['D1@Boss-Extrude1'] = 30 * mm")
print(sw.exec("for f in model.features(): print(f.Name)"))   # exec returns the printed text

Call	Does
swc.connect(session="client", start=False, timeout=300)	Attach to SOLIDWORKS (start=True launches it if needed) and load the add-in
sw.eval(expr) / sw(expr)	Evaluate; JSON-compatible results (numbers, strings, lists, dicts) come back as values, others as their repr string
sw.exec(code)	Run statements; returns the captured print output
sw.run(code)	Raw result dict: ok, stdout, result (repr), value (if JSON-able), error
sw.reset()	Forget the session’s variables
sw.version()	Add-in version

Errors inside SOLIDWORKS raise swc.SwPyError with the remote traceback.

Sessions

Each client uses a named session (default "client"); variables persist between calls, so you can build state step by step in a notebook. Use different names to keep notebooks apart: swc.connect(session="study-1"). The editor pane uses its own session ("editor").

Example: a parameter study from Jupyter

import swpy.client as swc
import pandas as pd

sw = swc.connect()
rows = []
for t in [10, 15, 20, 25, 30]:
    sw.exec(f"model.dims['D1@Boss-Extrude1'] = {t} * mm")
    rows.append({"thickness_mm": t, "mass_kg": sw.eval("model.mass['mass']")})
pd.DataFrame(rows).plot(x="thickness_mm", y="mass_kg")

Each call is a round trip of about 3 ms plus the work inside SOLIDWORKS. For many small operations, send one larger piece of code instead of many tiny calls.

From Excel VBA, C#, Grasshopper …

Any COM client can call the add-in object directly:

' Excel VBA
Dim swApp As Object, swpy As Object, result As String
Set swApp = GetObject(, "SldWorks.Application")
Set swpy = swApp.GetAddInObject("SwPy.AddIn")
result = swpy.Execute("excel", "model.mass['mass']")
' result is JSON: {"ok": true, "stdout": "", "result": "0.12", "value": 0.12, "error": null}

// C#
dynamic sw = Marshal.GetActiveObject("SldWorks.Application");   // .NET Framework
dynamic swpy = sw.GetAddInObject("SwPy.AddIn");
string json = swpy.Execute("csharp", "doc.GetTitle()");

Execute(session, code) always returns a JSON string with the fields ok, stdout, result, value and error.