Add pip install cell to Colab notebooks (#862)

CHANGELOG.md

@@ -21,6 +21,7 @@
 * Updated Otter Grade Docker image to create an empty `submission_metadata.json` file in the grading image to prevent plugins from erroring per [#811](https://github.com/ucbds-infra/otter-grader/issues/811)
 * Added ability to monitor grading progress to Otter Grade per [#827](https://github.com/ucbds-infra/otter-grader/issues/827)
 * Added handling of student-created files with the `student_files` configuration in Otter Assign per [#737](https://github.com/ucbds-infra/otter-grader/issues/737)
+* Updated Otter Assign to add a cell to install Otter at the top of Colab notebooks per [#861](https://github.com/ucbds-infra/otter-grader/issues/861)
 
 **v5.7.1:**
 

otter/assign/cell_factory.py

@@ -54,7 +54,14 @@ def create_init_cells(self) -> list[nbformat.NotebookNode]:
         contents = f"# Initialize Otter\nimport otter\ngrader = otter.Notebook({args})"
         cell = nbformat.v4.new_code_cell(contents)
         lock(cell)
-        return [cell]
+
+        extra_cells = []
+        if self.assignment.runs_on == "colab":
+            pip_cell = nbformat.v4.new_code_cell("%pip install -q otter-grader")
+            lock(pip_cell)
+            extra_cells.append(pip_cell)
+
+        return extra_cells + [cell]
 
     def create_check_cells(self, question: QuestionConfig) -> list[nbformat.NotebookNode]:
         """

test/test_assign/files/gs-correct/autograder/generate-gradescope.ipynb

@@ -1,5 +1,17 @@
 {
  "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "deletable": false,
+    "editable": false
+   },
+   "outputs": [],
+   "source": [
+    "%pip install -q otter-grader"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,

test/test_assign/files/gs-correct/student/generate-gradescope.ipynb

@@ -1,5 +1,17 @@
 {
  "cells": [
+  {
+    "cell_type": "code",
+    "execution_count": null,
+    "metadata": {
+     "deletable": false,
+     "editable": false
+    },
+    "outputs": [],
+    "source": [
+     "%pip install -q otter-grader"
+    ]
+  },
   {
    "cell_type": "code",
    "execution_count": null,