BathAfrica: Add rewritten practical lesson with steps, code and expected results

2026-10-29T21:01:07Z

Add rewritten practical lesson with steps, code and expected results

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__NOTOC__
{{OpenSite scope}}
{{OpenSite lesson
|id=opensite.help.run-your-first-script
|summary=Run a small Python calculation and learn which output surface to read.
|prerequisites=An OpenSite development build with its matching embedded runtime. A system Python interpreter is not a replacement for the embedded OpenSite host.
|steps==== Choose console or editor ===
Use the interactive Console for a short expression. Use the Python workbench editor for a repeatable <code>.py</code> file. They share one interpreter and lane.

=== Enter the quantity lesson ===
Create a script containing the quantities example below. Save it before relying on its filename in tracebacks. Running an unsaved buffer does not save it.

=== Run the current file ===
Choose the Python workbench Run action. The workbench also supports running a selection or a current line; verify the intended scope before running.

=== Read Output ===
Workbench script stdout/stderr goes to the host Output panel, with source <code>python.script</code>. The interactive Console transcript is separate. {{MenuCommand|View → Show Output}} shows the shared panel.

=== Repeat deliberately ===
Rerun retains imports, variables and application state. Start with a fresh document or explicit variables when the example depends on a clean state.

|result=The quantity lesson reports a total of 3650 mm. The same script can be used in the matching headless OpenSite host.
|limitations=A script has the privileges of the embedded host. Run only trusted code. Avoid starting a second operation while the shared execution lane is busy.
}}

== Complete example ==
{{Code|lang=python|code=<nowiki>import opensite

span = opensite.parse_quantity("3.2 m")
extension = opensite.parse_quantity("450 mm")
total = opensite.add(span, extension)
print(f"Total: {total.value_in('mm'):.0f} mm")
assert abs(total.si_value - 3.65) < 1e-12

before = total.si_value
opensite.execute("units.set_profile", {"profile": "engineering_metric"})
print("Display:", opensite.format_quantity(total, "engineering_metric"))
assert total.si_value == before</nowiki>}}

<div class="os-page-nav">{{Docnav|OpenSite/Guides/Dimensionless material expressions|OpenSite/Guides/Discover commands|OpenSite/Guides|All guides}}</div>
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BathAfrica: Add rewritten practical lesson with steps, code and expected results