add support for notbook worksheets

Author: filipchristiansen

src/gitingest/notebook_utils.py

@@ -1,7 +1,9 @@
 """ Utilities for processing Jupyter notebooks. """
 
 import json
+import warnings
 from pathlib import Path
+from typing import Any
 
 
 def process_notebook(file: Path) -> str:
@@ -24,7 +26,23 @@ def process_notebook(file: Path) -> str:
         If an unexpected cell type is encountered.
     """
     with file.open(encoding="utf-8") as f:
-        notebook = json.load(f)
+        notebook: dict[str, Any] = json.load(f)
+
+    # Check if the notebook contains worksheets
+    if worksheets := notebook.get("worksheets"):
+        # https://github.com/ipython/ipython/wiki/IPEP-17:-Notebook-Format-4#remove-multiple-worksheets
+        #   "The `worksheets` field is a list, but we have no UI to support multiple worksheets.
+        #   Our design has since shifted to heading-cell based structure, so we never intend to
+        #   support the multiple worksheet model. The worksheets list of lists shall be replaced
+        #   with a single list, called `cells`."
+        warnings.warn("Worksheets are deprecated as of IPEP-17.", DeprecationWarning)
+
+        if len(worksheets) > 1:
+            warnings.warn(
+                "Multiple worksheets are not supported. Only the first worksheet will be processed.", UserWarning
+            )
+
+        notebook = worksheets[0]
 
     result = []