🪵 fs-tree-spec (tree_adapter)

Translate between ASCII “tree” text, JSON/YAML tree specs, and real directory structures.
This tiny Python utility helps you describe, version, and reproduce directory layouts in a portable, human-readable way.

✨ Features

• Parse ASCII "tree" text (like tree command output) → nested Python structure
• Scan existing directories (--from-fs) → generate tree specs
• Serialize / deserialize JSON and YAML tree specs
• Render a Unicode tree from structured data
• Validate naming rules (strict enforcement, no invalid characters)
• Compute a dry-run plan (--plan) of what would be created
• Apply (--apply) to actually build the filesystem
• Smart defaults: ignores __pycache__, .git, node_modules, etc.
• Optional YAML support via pip install fs-tree-spec[yaml]

🧩 Installation

pip install fs-tree-spec
# or with YAML support:
pip install fs-tree-spec[yaml]

After installation, the CLI command fs-tree-spec becomes available.

🧭 Usage (CLI)

Basic

# Plan creation from an ASCII spec
fs-tree-spec --from-ascii second_brain_tree.txt --root ./second-brain --plan

# Apply (actually create directories/files)
fs-tree-spec --from-ascii second_brain_tree.txt --root ./second-brain --apply

# Print as normalized ASCII and JSON
fs-tree-spec --from-ascii second_brain_tree.txt --print-tree --print-json

From JSON or YAML

fs-tree-spec --from-json my_tree.json --plan
fs-tree-spec --from-yaml my_tree.yaml --apply

From Existing Directory

Generate a tree spec by scanning an existing directory structure:

# Generate ASCII tree from current directory
fs-tree-spec --from-fs . --print-tree

# Generate JSON spec from a project
fs-tree-spec --from-fs ./my-project --print-json

# Generate YAML spec
fs-tree-spec --from-fs ./src --print-yaml

# Exclude root directory name from output
fs-tree-spec --from-fs ./my-project --print-tree --no-root-label

Default ignore patterns: __pycache__, *.pyc, .git, .venv, node_modules, .pytest_cache, .mypy_cache, .ruff_cache, *.egg-info, .DS_Store

# Custom ignore patterns
fs-tree-spec --from-fs . --print-tree --ignore "*.log" "tmp/" "build/"

# Disable default ignores (include everything)
fs-tree-spec --from-fs . --print-tree --ignore

📜 Example Input

ASCII tree text

second-brain/
├─ .env                      # API keys + config (not committed)
├─ pyproject.toml
├─ README.md
├─ data/
│  ├─ raw/
│  │  └─ apple_notes_export/
│  ├─ attachments/
│  │  └─ ...
│  ├─ processed/
│  │  ├─ notes.jsonl
│  │  ├─ attachments.jsonl
│  │  └─ urls.jsonl
└─ notebooks/
   └─ exploration.ipynb

Equivalent JSON

{
  "second-brain": {
    ".env": null,
    "pyproject.toml": null,
    "README.md": null,
    "data": {
      "raw": { "apple_notes_export": {} },
      "attachments": {},
      "processed": {
        "notes.jsonl": null,
        "attachments.jsonl": null,
        "urls.jsonl": null
      }
    },
    "notebooks": {
      "exploration.ipynb": null
    }
  }
}

Equivalent YAML

second-brain:
  .env: null
  pyproject.toml: null
  README.md: null
  data:
    raw:
      apple_notes_export: {}
    attachments: {}
    processed:
      notes.jsonl: null
      attachments.jsonl: null
      urls.jsonl: null
  notebooks:
    exploration.ipynb: null

🧠 Naming Rules (Enforced)

1. Names are single path segments (no / or \).
2. Names must be non-empty after trimming.
3. Names cannot be ., .., ..., or ….
4. Names cannot contain tree/box characters: `├└│─|+```
5. Inline comments begin with " #" and are ignored.
6. "..." and "…" lines are treated as placeholders only.
7. Conflicts between file vs. directory at same level raise an error.

🧪 Python API Example

Create from spec

from tree_adapter import parse_ascii_tree, plan_fs_from_tree, create_fs_from_tree

ascii_spec = Path("second_brain_tree.txt").read_text()
tree = parse_ascii_tree(ascii_spec)

# Inspect
print(plan_fs_from_tree(tree, "./second-brain"))

# Create directories and files
create_fs_from_tree(tree, "./second-brain", create_files=True)

Generate from existing directory

from tree_adapter import from_fs, to_ascii_tree, to_json, to_yaml

# Scan a directory
tree = from_fs("./my-project", include_root_label=True)

# Convert to different formats
print(to_ascii_tree(tree))
print(to_json(tree))
print(to_yaml(tree))  # requires PyYAML

# Custom ignore patterns
tree = from_fs("./src", ignore_patterns=["*.log", "tmp/"])

# Include everything (no filtering)
tree = from_fs("./src", ignore_patterns=[])

🛠️ Development

# Clone and set up development environment
git clone https://github.com/swoodeng/fs-tree-spec.git
cd fs-tree-spec

# Install dependencies with uv
uv sync --all-extras --dev

# Run tests
uv run pytest

# Run linters
uv run ruff check .
uv run black --check .
uv run mypy tree_adapter.py

Run locally:

uv run fs-tree-spec --from-ascii second_brain_tree.txt --plan

📦 Packaging

This project uses PEP 621 metadata and can be built with:

python -m build

⚖️ License

MIT License © 2025 Stephen Wood

💡 Inspiration

• tree command output formatting
• JSON/YAML for reproducible data models
• Cross-tool “infrastructure as text” patterns

🪴 Example Workflows

Spec → Filesystem

1. Write a tree spec in a README.md for documentation.
2. Extract the snippet and feed it to fs-tree-spec --from-ascii.
3. Plan or apply to generate the directory structure for new projects.
4. Optionally export the same spec to JSON or YAML for automation.

Filesystem → Spec

1. Scan an existing project with fs-tree-spec --from-fs ./project --print-tree.
2. Document by copying the output into your README.
3. Export to JSON/YAML for programmatic use or version control.
4. Recreate the structure elsewhere with --apply.

"Describe once. Recreate anywhere."