New Autograde Preprocessor: IgnorePattern (#1904)

* Create IgnorePattern Preprocessor

* Disable and add to the list by default

nbgrader/converters/autograde.py

@@ -9,7 +9,7 @@
 from .base import BaseConverter, NbGraderException
 from ..preprocessors import (
     AssignLatePenalties, ClearOutput, DeduplicateIds, OverwriteCells, SaveAutoGrades,
-    Execute, LimitOutput, OverwriteKernelspec, CheckCellMetadata)
+    Execute, LimitOutput, OverwriteKernelspec, CheckCellMetadata, IgnorePattern)
 from ..api import Gradebook, MissingEntry
 from .. import utils
 
@@ -61,6 +61,7 @@ def _output_directory(self) -> str:
     ]).tag(config=True)
     autograde_preprocessors = List([
         Execute,
+        IgnorePattern,
         ClearMetadataPreprocessor,
         LimitOutput,
         SaveAutoGrades,

nbgrader/preprocessors/__init__.py

@@ -17,6 +17,7 @@
 from .clearhiddentests import ClearHiddenTests
 from .clearmarkingscheme import ClearMarkScheme
 from .overwritekernelspec import OverwriteKernelspec
+from .ignorepattern import IgnorePattern
 
 __all__ = [
     "AssignLatePenalties",
@@ -37,4 +38,5 @@
     "ClearHiddenTests",
     "ClearMarkScheme",
     "OverwriteKernelspec",
+    "IgnorePattern",
 ]

nbgrader/preprocessors/ignorepattern.py

@@ -0,0 +1,31 @@
+from . import NbGraderPreprocessor
+
+from traitlets import Unicode, Bool
+from nbformat.notebooknode import NotebookNode
+from nbconvert.exporters.exporter import ResourcesDict
+from typing import Tuple
+import re
+
+
+class IgnorePattern(NbGraderPreprocessor):
+    """Preprocessor for removing cell outputs that match a particular pattern"""
+
+    pattern = Unicode("", help="The regular expression to remove from stderr").tag(config=True)
+    enabled = Bool(False, help="Whether to use this preprocessor when running nbgrader").tag(config=True)
+
+    def preprocess_cell(self,
+                        cell: NotebookNode,
+                        resources: ResourcesDict,
+                        cell_index: int
+                        ) -> Tuple[NotebookNode, ResourcesDict]:
+
+        if self.pattern and cell.cell_type == "code":
+            new_outputs = []
+            for output in cell.outputs:
+                if output.output_type == "stream" and output.name == "stderr" \
+                    and re.search(self.pattern, output.text):
+                        continue
+                new_outputs.append(output)
+            cell.outputs = new_outputs
+
+        return cell, resources

nbgrader/tests/preprocessors/files/warning-pattern.ipynb

@@ -0,0 +1,82 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "efd8b463-ea80-4620-b01b-1382a56e7836",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "[W NNPACK.cpp:64] Could not initialize NNPACK! Reason: Unsupported hardware.\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "5"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "import torch\n",
+    "layer = torch.nn.Conv2d(1, 32, 3, stride=1, padding=1)\n",
+    "x = torch.randn(1, 1, 28, 28)\n",
+    "y = layer(x)\n",
+    "5"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "2a2b6474-f64b-4c28-ac83-5d1c7bbfd92f",
+   "metadata": {
+    "tags": []
+   },
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "/tmp/ipykernel_522/3731920106.py:3: UserWarning: This is a warning message\n",
+      "  warnings.warn(\"This is a warning message\")\n"
+     ]
+    }
+   ],
+   "source": [
+    "import warnings\n",
+    "\n",
+    "warnings.warn(\"This is a warning message\")"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.12"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

nbgrader/tests/preprocessors/test_ignorepattern.py

@@ -0,0 +1,40 @@
+import pytest
+import os
+
+from ...preprocessors import IgnorePattern
+from .base import BaseTestPreprocessor
+
+
+@pytest.fixture
+def preprocessor():
+    pp = IgnorePattern()
+    pp.pattern = r"\[.*\.cpp.*\] Could not initialize NNPACK! Reason: Unsupported hardware."
+    return pp
+
+
+class TestIgnorePattern(BaseTestPreprocessor):
+
+    def test_remove_matching_output(self, preprocessor):
+        nb = self._read_nb(os.path.join("files", "warning-pattern.ipynb"))
+        cell = nb.cells[0]
+
+        outputs = cell.outputs
+        assert len(outputs) == 2
+
+        cell, _ = preprocessor.preprocess_cell(cell, {}, 0)
+
+        assert len(cell.outputs) == 1
+
+
+    def test_skip_nonmatching_output(self, preprocessor):
+        nb = self._read_nb(os.path.join("files", "warning-pattern.ipynb"))
+        cell = nb.cells[1]
+
+        outputs = cell.outputs
+        assert len(outputs) == 1
+
+        cell, _ = preprocessor.preprocess_cell(cell, {}, 1)
+
+        assert len(cell.outputs) == 1
+        assert cell.outputs[0].name == "stderr"
+