Collapse Output

Quarto Extension

Author

Installation

quarto add mcanouil/quarto-collapse-output@1.5.0

This will install the extension under the _extensions subdirectory.

If you are using version control, you will want to check in this directory.

Usage

Add the filter to your document’s front matter:

filters:
  - collapse-output

Configuration

extensions:
  collapse-output:
    method: lua
    collapse-all-outputs: false
    default-open: false
    auto-collapse-size: 6
    output-types: stdout, stderr, display
    summary-template: "{type} ({lines} lines)"
    summaries:
      stdout: "Console output"
      stderr: "Warnings and errors"

Examples

Basic Example with Text Output

This example demonstrates collapsing simple text output. The summary-template renders as Standard Output (N lines) because no per-cell output-summary is set.

```{python}
#| label: code

group = ["Ctl"] * 10 + ["Trt"] * 10
ctl = [4.17, 5.58, 5.18, 6.11, 4.50, 4.61, 5.17, 4.53, 5.33, 5.14]
trt = [4.81, 4.17, 4.41, 3.59, 5.87, 3.83, 6.03, 4.89, 4.32, 4.69]
weight = ctl + trt

mean_ctl = sum(ctl) / len(ctl)
mean_trt = sum(trt) / len(trt)
diff = mean_trt - mean_ctl

print(f"Mean (Ctl): {mean_ctl:.2f}")
print(f"Mean (Trt): {mean_trt:.2f}")
print(f"Difference: {diff:.2f}")
```

Console output

Mean (Ctl): 5.03
Mean (Trt): 4.66
Difference: -0.37

Cell-Level Summary Override

The explicit output-summary wins over the document template.

```{python}
#| label: explicit-summary

print(f"Range (Ctl): {min(ctl):.2f} to {max(ctl):.2f}")
print(f"Range (Trt): {min(trt):.2f} to {max(trt):.2f}")
```

Click to view summary statistics

Range (Ctl): 4.17 to 6.11
Range (Trt): 3.59 to 6.03

Cell Starting Open

This cell uses output-open: true to opt out of the closed default for one cell only.

```{python}
#| label: open-cell

print("This output starts expanded.")
```

Console output

This output starts expanded.

Auto-Collapse Threshold

This cell is shorter than auto-collapse-size: 6 lines, so it would honour default-open. A longer output (below) is forced closed by the threshold.

```{python}
#| label: short-output

print("Line 1")
print("Line 2")
```

Console output

Line 1
Line 2

```{python}
#| label: long-output

for i in range(1, 11):
  print(f"Long output line {i}")
```

Console output

Long output line 1
Long output line 2
Long output line 3
Long output line 4
Long output line 5
Long output line 6
Long output line 7
Long output line 8
Long output line 9
Long output line 10

Example with Table Output

Display outputs use the Display Output ({lines} lines) label.

```{python}
#| label: table

import polars as pl

df = pl.DataFrame({
  "Group": group,
  "Weight": weight
})

df
```

Display Output (1 lines)

shape: (20, 2)

Group	Weight
str	f64
"Ctl"	4.17
"Ctl"	5.58
"Ctl"	5.18
"Ctl"	6.11
"Ctl"	4.5
…	…
"Trt"	3.83
"Trt"	6.03
"Trt"	4.89
"Trt"	4.32
"Trt"	4.69

Example with Matplotlib Figure

```{python}
#| label: figure-1

import matplotlib.pyplot as plt

plt.boxplot([ctl, trt], tick_labels=["Ctl", "Trt"])
plt
```

Figure 1

Example with Plotnine Figure

```{python}
#| label: figure-2

from plotnine import ggplot, aes, geom_boxplot, labs
import polars as pl

df = pl.DataFrame({
  "Group": group,
  "Weight": weight
})

(
  ggplot(df.to_pandas()) +
    aes(x="Group", y="Weight") +
    geom_boxplot() +
    labs(title="Boxplot of Weight by Group")
)
```

Figure 2

Use Cases

The collapse output extension is particularly useful for:

Long outputs: Hide lengthy console output, tables, or plots by default.
Tutorial documents: Keep code visible whilst hiding output until needed.
Reports: Show results on demand without cluttering the main document.
Interactive exploration: Allow readers to selectively view outputs of interest.

Notes

Note

The output-fold code cell option only works with HTML output formats.
When using the Lua method (default), the collapse is applied at build time.
When using the JavaScript method, the collapse happens in the browser.
auto-collapse-size forces outputs closed even when default-open (or output-open) is true.
Both output-fold and output-summary are code cell options (use #| prefix).