Robust conversion of metadata to YAML #99

jupytext/header.py

@@ -3,12 +3,15 @@
 
 import re
 import yaml
+from yaml.representer import SafeRepresenter
 import nbformat
 from nbformat.v4.nbbase import new_raw_cell
 from .version import __version__
 from .cell_to_text import comment_lines
 from .languages import _SCRIPT_EXTENSIONS
 
+SafeRepresenter.add_representer(nbformat.NotebookNode, SafeRepresenter.represent_dict)
+
 _HEADER_RE = re.compile(r"^---\s*$")
 _BLANK_RE = re.compile(r"^\s*$")
 _JUPYTER_RE = re.compile(r"^jupyter\s*:\s*$")
@@ -25,12 +28,6 @@ def insert_or_test_version_number():
     return INSERT_AND_CHECK_VERSION_NUMBER
 
 
-def _as_dict(metadata):
-    if isinstance(metadata, nbformat.NotebookNode):
-        return {k: _as_dict(metadata[k]) for k in metadata.keys()}
-    return metadata
-
-
 def uncomment_line(line, prefix):
     """Remove prefix (and space) from line"""
     if not prefix:
@@ -91,7 +88,7 @@ def metadata_and_cell_to_header(notebook, text_format, ext):
                 skipline = not cell.metadata.get('noskipline', False)
                 notebook.cells = notebook.cells[1:]
 
-    metadata = _as_dict(notebook.get('metadata', {}))
+    metadata = notebook.get('metadata', {})
 
     if insert_or_test_version_number():
         metadata.setdefault('jupytext', {})['text_representation'] = {

tests/notebooks/ipynb_py/notebook_with_complex_metadata.ipynb

@@ -0,0 +1,46 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "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": "3.5.1"
+  }, 
+  "widgets": {
+   "state": {
+    "a65a11f142ca44eebc913788d256adcb": {
+     "views": [
+      {
+       "cell_index": 92
+      }
+     ]
+    }
+   }, 
+   "version": "1.2.0"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

tests/notebooks/mirror/ipynb_to_Rmd/notebook_with_complex_metadata.Rmd

@@ -0,0 +1,27 @@
+---
+jupyter:
+  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: 3.5.1
+  widgets:
+    state:
+      a65a11f142ca44eebc913788d256adcb:
+        views:
+        - cell_index: 92
+    version: 1.2.0
+---
+
+```{python}
+
+```

tests/notebooks/mirror/ipynb_to_md/notebook_with_complex_metadata.md

@@ -0,0 +1,27 @@
+---
+jupyter:
+  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: 3.5.1
+  widgets:
+    state:
+      a65a11f142ca44eebc913788d256adcb:
+        views:
+        - cell_index: 92
+    version: 1.2.0
+---
+
+```python
+
+```

tests/notebooks/mirror/ipynb_to_percent/notebook_with_complex_metadata.py

@@ -0,0 +1,26 @@
+# ---
+# jupyter:
+#   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: 3.5.1
+#   widgets:
+#     state:
+#       a65a11f142ca44eebc913788d256adcb:
+#         views:
+#         - cell_index: 92
+#     version: 1.2.0
+# ---
+
+# %%
+

tests/notebooks/mirror/ipynb_to_script/notebook_with_complex_metadata.py

@@ -0,0 +1,25 @@
+# ---
+# jupyter:
+#   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: 3.5.1
+#   widgets:
+#     state:
+#       a65a11f142ca44eebc913788d256adcb:
+#         views:
+#         - cell_index: 92
+#     version: 1.2.0
+# ---
+
+

tests/notebooks/mirror/ipynb_to_sphinx/notebook_with_complex_metadata.py

@@ -0,0 +1,25 @@
+# ---
+# jupyter:
+#   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: 3.5.1
+#   widgets:
+#     state:
+#       a65a11f142ca44eebc913788d256adcb:
+#         views:
+#         - cell_index: 92
+#     version: 1.2.0
+# ---
+
+