Phys130b Notebook

Fallback / de-escalation

1. If validation reports corruption, stop feature work—repair using rules/troubleshooting-ipynb.md, re-validate, then continue.
2. If unsure about cell indices, read the notebook and print a cell summary before writing.
3. If a write might conflict with parallel edits, prefer one notebook at a time and re-read before save.

Absolute rules

1. NEVER NotebookEdit on .ipynb.
2. NEVER Edit/Write on .ipynb in Cowork—use Bash + json.load / json.dump.
3. json.dump(nb, f, indent=1, ensure_ascii=False) always.
4. text_to_source for markdown strings—canonical implementation: skills/notebook-writer/scripts/safe_edit.py (same logic as rules/notebook-editing.md).
5. Read before write; validate after write.

Workflow

import json

def text_to_source(text):
    lines = text.split('\n')
    source = []
    for i, line in enumerate(lines):
        if i < len(lines) - 1:
            source.append(line + '\n')
        else:
            if line:
                source.append(line)
    return source

with open(path) as f:
    nb = json.load(f)
# inspect len(nb['cells']), then:
nb['cells'][CELL_INDEX]['source'] = text_to_source(new_content)
with open(path, 'w') as f:
    json.dump(nb, f, indent=1, ensure_ascii=False)

Validation (after every write)

python3 .claude/skills/notebook-writer/scripts/safe_edit.py validate path/to.ipynb

For broader checks (structure, MyST, notation heuristics):

python3 .claude/scripts/validate_project.py --scope <chapter-or-file-stem>

Full list of checks: see former validate playbook—corruption, cell counts/titles, $$ blank lines, banned patterns (---, nested :::, plt.show(), etc.), notation hints in math (script docstring).

Report results in a small table if many files: | Notebook | Corruption | Structure | Other |.

Fix workflow (from feedback)

1. json.load the notebook; locate cell/line from the report.
2. Classify: char-by-char / missing \n / collapsed line / content violation of rules/ (architecture, MyST, style).
3. Patch with json.dump; validate; update progress.md or annotate feedback.md when resolved.

References

• CLAUDE.md, .claude/README.md, rules/notebook-editing.md, rules/tooling-security.md, rules/validation.md, rules/troubleshooting-ipynb.md
• _refs/ (project root): Professor's original lecture notes. Read the corresponding _refs/ file before writing or rewriting any derivation or physics content. See CLAUDE.md § "Reference materials" for the chapter-to-file mapping.