Add skip-execution cell tag functionality

nbclient/client.py

@@ -139,6 +139,16 @@ class NotebookClient(LoggingConfigurable):
         ),
     ).tag(config=True)
 
+    skip_cells_with_tag: str = Unicode(
+        'skip-execution',
+        help=dedent(
+            """
+            Name of the cell tag to use to,
+            to denote a cell that should be skipped.
+            """
+        ),
+    ).tag(config=True)
+
     extra_arguments: t.List = List(Unicode()).tag(config=True)
 
     kernel_name: str = Unicode(
@@ -802,6 +812,10 @@ async def async_execute_cell(
         if cell.cell_type != 'code' or not cell.source.strip():
             self.log.debug("Skipping non-executing cell %s", cell_index)
             return cell
+
+        if self.skip_cells_with_tag in cell.metadata.get("tags", []):
+            self.log.debug("Skipping tagged cell %s", cell_index)
+            return cell
 
         if self.record_timing and 'execution' not in cell['metadata']:
             cell['metadata']['execution'] = {}

nbclient/tests/files/Skip Execution with Cell Tag.ipynb

@@ -0,0 +1,37 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "source": [
+    "print(\"a long running cell\")"
+   ],
+   "outputs": [],
+   "metadata": {
+    "tags": [
+     "skip-execution"
+    ]
+   }
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "source": [
+    "print('ok')"
+   ],
+   "outputs": [
+    {
+     "output_type": "stream",
+     "name": "stdout",
+     "text": [
+      "ok\n"
+     ]
+    }
+   ],
+   "metadata": {}
+  }
+ ],
+ "metadata": {},
+ "nbformat": 4,
+ "nbformat_minor": 1
+}

nbclient/tests/test_client.py

@@ -257,6 +257,7 @@ def notebook_resources():
         ("JupyterWidgets.ipynb", dict(kernel_name="python")),
         ("Skip Exceptions with Cell Tags.ipynb", dict(kernel_name="python")),
         ("Skip Exceptions.ipynb", dict(kernel_name="python", allow_errors=True)),
+        ("Skip Execution with Cell Tag.ipynb", dict(kernel_name="python")),
         ("SVG.ipynb", dict(kernel_name="python")),
         ("Unicode.ipynb", dict(kernel_name="python")),
         ("UnicodePy3.ipynb", dict(kernel_name="python")),