Set consistent widths for table columns.
HTML: A colgroup applies presentation to whole columns without repeating styles on every cell.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Example</title>
</head>
<body>
<table><colgroup><col style="width:120px"><col style="width:80px"></colgroup><tr><td>Name</td><td>Score</td></tr><tr><td>Ada</td><td>98</td></tr></table>
</body>
</html>Expected output EXAMPLE
The first table column is approximately 120 pixels wide and the second approximately 80 pixels wide; cell borders can affect the measured widths.
Details
Save as example.html and open in a modern browser. The output describes browser behavior verified with DOM and interaction assertions. A colgroup applies presentation to whole columns without repeating styles on every cell.
Tested on Ubuntu 24.04.5 LTS · · Chromium 141.0.7390.37 · libc6 2.39-0ubuntu8.9; Playwright 1.56.0
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged) / C.UTF-8
- Interpreter invocation
Chromium: open example.html; execute the published browser assertions- Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd- Code SHA-256
5bef4b88c2867235a333d6518596b600ffa5f5b7ffd55a9e4dca06f305eb09fb- Dependencies
- libc6 2.39-0ubuntu8.9; Playwright 1.56.0
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
# No input files required.
Observed standard output
Expected output describes the rendered page. The standard-output record below is the browser test harness receipt; the additional assertions check the result and interactions.
Set consistent widths for table columns: browser checks passed.
Exit code: 0. Standard error: empty. Validation: Shape/content assertions. System-dependent values above are one recorded run.
Additional assertions that passed
Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.
cells=page.locator('tr').first.locator('td')
a=await cells.nth(0).bounding_box(); b=await cells.nth(1).bounding_box()
assert a['width']>=118 and b['width']>=78 and a['width']>b['width']