📚 Shelfie

Simple filesystem-based structured storage for data with metadata

Shelfie helps you organize your data files in a structured, hierarchical way while automatically managing metadata. Think of it as a filing system that creates organized directories based on your data's characteristics and keeps track of important information about each dataset.

🎯 Why Shelfie?

• Organized: Automatically creates directory structures based on your data's fields
• Metadata-aware: Stores attributes alongside your data files
• Flexible: Works with any data that can be saved as CSV, JSON, or pickle
• Simple: Intuitive API for creating and reading structured datasets
• Discoverable: Easy to browse and understand your data organization in the filesystem

Shelfie is meant to be an in between a full database and having to create a wrapper for a filesystem based storage for each project.

🏗️ How It Works

Conceptual Model: Database Relations → Directory Structure

Shelfie translates database-style relationships into filesystem organization:

Database Thinking          →    Filesystem Result
─────────────────────────────────────────────────────
Tables: [experiments]      →    Directory Level 1
Tables: [models]           →    Directory Level 2  
Tables: [dates]            →    Directory Level 3
Columns: epochs, lr        →    metadata.json
Data: results.csv          →    Attached files

Visual Concept

Root Directory
├── .shelfie.pkl                    # Shelf configuration
├── experiment_1/                   # Field 1 value
│   ├── random_forest/              # Field 2 value  
│   │   ├── 2025-06-12/             # Field 3 value (auto-generated date)
│   │   │   ├── metadata.json       # Stored attributes
│   │   │   ├── results.csv         # Your data files
│   │   │   └── model.pkl          # More data files
│   │   └── gradient_boost/
│   │       └── 2025-06-12/
│   │           ├── metadata.json
│   │           └── results.csv
│   └── neural_network/
│       └── 2025-06-12/
│           ├── metadata.json
│           └── predictions.csv
└── experiment_2/
    └── ...

The Pattern

Shelfie = Filesystem-Based Relational Design

1. Fields → Directory hierarchy (what you'd normalize into separate tables)
2. Attributes → Stored metadata (what you'd store as columns in those tables)
3. Data → Files attached to each record (the actual data your database would reference)
4. File Paths → Automatically tracked as filename_path__ in metadata

Traditional Database:

SELECT r.accuracy, e.name, m.type, r.epochs 
FROM results r
JOIN experiments e ON r.experiment_id = e.id  
JOIN models m ON r.model_id = m.id
WHERE e.date = '2025-06-12'

Shelfie Equivalent:

data = load_from_shelf("./experiments")
results_df = data['results']  # Already has experiment, model, date columns!
filtered = results_df[results_df['date'] == '2025-06-12']

🚀 Quick Start

Installation

pip install shelfie

Basic Example

import pandas as pd
from shelfie import Shelf, DateField

# Create a shelf for ML experiments
ml_shelf = Shelf(
    root="./experiments",
    fields=["experiment", "model", DateField("date")],  # Directory structure
    attributes=["epochs", "learning_rate"]              # Required metadata
)

# Create a new experiment record
experiment = ml_shelf.create(
    experiment="baseline",
    model="mlp", 
    epochs=100,
    learning_rate=0.001  # Typical learning rate for neural networks
)

# Attach your results
results_df = pd.DataFrame({
    "accuracy": [0.85, 0.87, 0.89], 
    "loss": [0.45, 0.32, 0.28],
    "epoch": [1, 2, 3]
})

experiment.attach(results_df, "results.csv")

This creates:

experiments/
└── baseline/
    └── mlp/
        └── 2025-06-12/
            ├── metadata.json  # {"epochs": 100, "learning_rate": 0.001, "results_path__": "/path/to/results.csv"}
            └── results.csv    # Your data

📖 Detailed Examples

1. ML Experiment Tracking

Think of this as three related database tables:

• experiments table → project field
• models table → model_type field
• runs table → date field
• Attributes: dataset, hyperparams, notes

from shelfie import Shelf, DateField, TimestampField
import pandas as pd

# Set up experiment tracking (defines your "table" relationships)
experiments = Shelf(
    root="./ml_experiments",
    fields=["project", "model_type", DateField("date")],  # Your table hierarchy
    attributes=["dataset", "hyperparams", "notes"]        # Your table columns
)

# Log different experiments
mlp_experiment = experiments.create(
    project="customer_churn",
    model_type="mlp",
    dataset="v2_cleaned",
    hyperparams={"hidden_layers": [128, 64, 32], "dropout": 0.3, "activation": "relu"},
    notes="Multi-layer perceptron with dropout regularization"
)

# Attach multiple files
mlp_experiment.attach(train_results, "training_metrics.csv")
mlp_experiment.attach(test_results, "test_results.csv")
mlp_experiment.attach(feature_importance, "feature_importance.csv")

# Try a different model
cnn_experiment = experiments.create(
    project="customer_churn",
    model_type="cnn",
    dataset="v2_cleaned", 
    hyperparams={"filters": [32, 64, 128], "kernel_size": 3, "learning_rate": 0.0001},
    notes="Convolutional neural network approach"
)

2. Sales Data by Region and Time

Database equivalent:

• regions table → region field
• time_periods table → year, quarter fields
• Attributes: analyst, report_type, data_source

# Organize sales data by geography and time (multi-table relationship)
sales_shelf = Shelf(
    root="./sales_data",
    fields=["region", "year", "quarter"],                    # Geographic + temporal tables
    attributes=["analyst", "report_type", "data_source"]     # Report metadata columns
)

# Store Q1 data for North America
na_q1 = sales_shelf.create(
    region="north_america",
    year="2025", 
    quarter="Q1",
    analyst="john_doe",
    report_type="quarterly_summary",
    data_source="salesforce"
)

sales_data = pd.DataFrame({
    "product": ["A", "B", "C"],
    "revenue": [150000, 200000, 180000],
    "units_sold": [1500, 2000, 1800]
})

na_q1.attach(sales_data, "quarterly_sales.csv")

3. Survey Data Organization

Database tables: survey_types → demographics → timestamps

# Organize survey responses by type and demographics
surveys = Shelf(
    root="./survey_data",
    fields=["survey_type", "demographic", TimestampField("timestamp")],  # Survey taxonomy
    attributes=["sample_size", "methodology", "response_rate"]            # Survey metadata
)

# Store customer satisfaction survey
survey = surveys.create(
    survey_type="customer_satisfaction",
    demographic="millennials",
    sample_size=1000,
    methodology="online_panel", 
    response_rate=0.23
)

responses = pd.DataFrame({
    "question_id": [1, 2, 3, 4, 5],
    "avg_score": [4.2, 3.8, 4.1, 3.9, 4.0],
    "response_count": [920, 915, 898, 901, 911]
})

survey.attach(responses, "responses.csv")

📊 Reading Your Data Back

The Magic: Automatic JOIN Operations

Unlike databases where you need explicit JOINs, Shelfie automatically combines your "table" relationships:

from shelfie import load_from_shelf

# Load all data from experiments shelf
data = load_from_shelf("./ml_experiments")

# Returns a dictionary of DataFrames - like running multiple JOINed queries:
# {
#   'metadata': All experiment metadata with project+model+date info,
#   'training_metrics': Training data with experiment context automatically joined,
#   'test_results': Test data with experiment context automatically joined,
#   ...
# }

# Analyze all your experiments - no JOINs needed!
print(data['metadata'])  # Overview of all experiments
print(data['training_metrics'])  # All training metrics with full context

# Note: File paths are stored as filename_path__ columns (e.g., 'training_metrics_path__')

What you get automatically:

• Denormalized DataFrames: Each CSV gets experiment+model+date columns added
• Full Context: Every row knows its complete "relational" context
• No JOIN complexity: Relationships are already materialized
• Pandas-ready: Immediate analysis without SQL knowledge

Each DataFrame automatically includes:

• Original data columns: Your actual data
• Attribute columns: Metadata from your "table columns" (hyperparams, notes, etc.)
• Field columns: Directory structure as relational context (project, model_type, date)
• File path columns: References as filename_path__ columns

🛠️ Advanced Features

Custom Fields with Defaults

from shelfie import Field, DateField, TimestampField

# Field with a default value
shelf = Shelf(
    root="./data",
    fields=[
        "experiment",
        Field("environment", default="production"),  # Always "production" unless specified
        DateField("date"),                          # Auto-generates today's date
        TimestampField("timestamp")                 # Auto-generates current timestamp
    ],
    attributes=["version"]
)

# Only need to specify non-default fields
record = shelf.create(
    experiment="test_1",
    version="1.0"
)
# Creates: ./data/test_1/production/2025-06-12/2025-06-12_14-30-45/
# Metadata includes: version_path__ for any attached files

Multiple File Types

# Attach different file types
record.attach(results_df, "results.csv")           # CSV
record.attach(model_config, "config.json")         # JSON  
record.attach(trained_model, "model.pkl")          # Pickle
record.attach(report_text, "summary.txt")          # Text

Loading Existing Shelves

# Load a shelf that was created elsewhere
existing_shelf = Shelf.load_from_root("./experiments")

# Continue adding to it
new_experiment = existing_shelf.create(
    experiment="advanced",
    model="transformer",
    epochs=50,
    learning_rate=0.0001  # Lower learning rate for transformer models
)

🗂️ Directory Structure Examples

Before Shelfie

my_project/
├── experiment1_mlp_results.csv
├── experiment1_mlp_model.pkl  
├── experiment2_cnn_results.csv
├── experiment2_cnn_model.pkl
├── baseline_test_data.csv
├── advanced_test_data.csv
└── notes.txt  # Which file belongs to what?

After Shelfie

my_project/
├── baseline/
│   ├── mlp/
│   │   └── 2025-06-12/
│   │       ├── metadata.json      # {"epochs": 100, "lr": 0.001, "results_path__": "/path/results.csv"}
│   │       ├── results.csv
│   │       └── model.pkl
│   └── cnn/
│       └── 2025-06-12/
│           ├── metadata.json      # {"epochs": 200, "lr": 0.0001, "results_path__": "/path/results.csv"}
│           ├── results.csv
│           └── model.pkl
└── advanced/
    └── transformer/
        └── 2025-06-12/
            ├── metadata.json      # {"epochs": 50, "lr": 0.0001, "results_path__": "/path/results.csv"}
            ├── results.csv
            └── model.pkl

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📄 License

This project is licensed under the MIT License.

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Happy organizing! 📚✨