6. Packages

Any pure-Python or binary wheel from PyPI works in SwPy scripts: numpy, pandas, openpyxl, scipy, matplotlib … Declare what a script needs in a # r: comment (the same convention as Rhino 8):

# r: openpyxl
import openpyxl

wb = openpyxl.Workbook()
ws = wb.active
ws.append(["Dimension", "Value (mm)"])
for name, value in model.dims.items().items():
    ws.append([name, to(value, mm)])
wb.save(r"C:\temp\dimensions.xlsx")

When the script runs, missing packages are installed first (progress appears in the output panel), then the script continues. Later runs start immediately because the package is already there.

Syntax

# r: numpy
# r: pandas>=2, openpyxl
# r: requests==2.32.3

• One or more packages per line, separated by commas or spaces; several # r: lines are allowed, anywhere in the script.
• Use pip requirement syntax: a package name, optional extras and version specifiers (requests[socks]>=2.31,<3). An exact pin (==) is checked against the installed version and re-installed if different; other specifiers install the package if it is missing.
• For safety only PyPI package names are accepted: pip options (--index-url ...), URLs and paths are rejected with an error, so a script header cannot point pip at another package source.

Where packages go

Packages are installed per user, into %LOCALAPPDATA%\SwPy\site-packages\py3.12 - never into a Python installation, and no admin rights are needed. This folder is on sys.path for every script and the REPL, so once installed a package can also be imported without the # r: line (keep the line anyway, so the script works on other machines).

To remove packages, delete their folders there (with SOLIDWORKS closed), or the whole folder to start over.

Notes

• Installing needs internet access to PyPI (or your configured pip index: pip reads the usual %APPDATA%\pip\pip.ini).
• Packages with compiled parts must offer a wheel for Python 3.12, Windows x64 (almost all popular ones do).
• Large packages (numpy, pandas) take a few seconds to import the first time in a session; after that imports are instant because the session keeps them.
• GUI toolkits that need their own event loop (tkinter main loops, Qt apps) do not mix well with SOLIDWORKS’ UI thread. Use them from an external Python instead.