Add export button to experiments_widget()

docs/changes/newsfragments/7772.improved

@@ -0,0 +1,5 @@
+The table created by experiments_widget() now has a column of buttons by which individual datasets can be exported as ASCII files. This is a user-friendly way to use the qcode.dataset.export() method.
+
+To demo this feature, run
+> experiments_widget(sort_by="timestamp")
+in Jupyter, and click on one of the cells in the "Export" column.

src/qcodes/interactive_widget.py

@@ -8,6 +8,7 @@
 import traceback
 from datetime import datetime
 from functools import partial, reduce
+from pathlib import Path
 from typing import TYPE_CHECKING, Any, Literal
 
 from ipywidgets import (  # type: ignore[import-untyped]
@@ -442,6 +443,21 @@ def _get_plot_button(ds: DataSetProtocol, tab: Tab) -> Button:
     )
 
 
+def _get_export_button(
+    ds: DataSetProtocol, tab: Tab
+) -> Button:  # New button in the table to export each dataset
+    return button(
+        "",
+        "warning",
+        tooltip="Click to export this DataSet as ASCII.",
+        on_click=lambda _: ds.export(
+            "csv",
+            path=Path.cwd() / "export",
+        ),
+        button_kwargs=dict(icon="file-export"),
+    )
+
+
 def _experiment_widget(
     data_sets: Iterable[DataSetProtocol], tab: Tab
 ) -> GridspecLayout:
@@ -457,6 +473,7 @@ def _experiment_widget(
         "Notes",
         "Snapshot",
         "Plot",
+        "Export",
     ]
 
     header = {n: button(n, "info") for n in header_names}
@@ -471,6 +488,7 @@ def _experiment_widget(
         row["MSMT Time"] = _get_timestamp_button(ds)
         row["Snapshot"] = _get_snapshot_button(ds, tab)
         row["Plot"] = _get_plot_button(ds, tab)
+        row["Export"] = _get_export_button(ds, tab)
         rows.append(row)
 
     grid = GridspecLayout(n_rows=len(rows), n_columns=len(header_names))

tests/test_interactive_widget.py

@@ -75,6 +75,13 @@ def test_snapshot_button(tab, standalone_parameters_dataset) -> None:
     assert "snapshot" in tab.get_title(1)
 
 
+def test_export_button(tab, standalone_parameters_dataset) -> None:
+    ds = standalone_parameters_dataset
+    export_button = interactive_widget._get_export_button(ds, tab)
+    export_button.click()
+    time.sleep(0.5)  # after click
+
+
 @patch("matplotlib.pyplot.show")
 def test_plot_button(tab, standalone_parameters_dataset) -> None:
     ds = standalone_parameters_dataset