feathertail 0.1.0

A tiny, fast, Rust-backed transformation core for Python table data

🪶 feathertail

High-performance Python DataFrame library powered by Rust, designed for flexibility, speed, and clear schema handling.

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✨ Features

• ✅ Build TinyFrame from Python dict records (from_dicts)
• ✅ Support for nested types (Mixed, OptMixed) and optional columns
• ✅ Automatic type inference
• ✅ Fill missing values (fillna)
• ✅ Cast columns to different types (cast_column)
• ✅ Edit columns with custom Python functions (edit_column)
• ✅ Drop or rename columns
• ✅ Simple group-by aggregations with TinyGroupBy
• ✅ Export to Python dicts (to_dicts)
• ✅ Lightweight, fast, and pure Rust core

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📦 Installation

pip install feathertail

Or, from local source:

pip install -e .

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🧑‍💻 Usage

import feathertail as ft

records = [
    {"name": "Alice", "age": 30, "city": "New York", "score": 95.5},
    {"name": "Bob", "age": None, "city": "Paris", "score": 85.0},
    {"name": "Charlie", "age": 25, "city": "New York", "score": None},
]

# Create frame
frame = ft.TinyFrame.from_dicts(records)

print(frame)
print(frame.to_dicts())

# Fill missing values
frame.fillna({"age": 20, "score": 0.0})
print(frame.to_dicts())

# Cast score column to float explicitly
frame.cast_column("score", float)

# Edit city column to uppercase
frame.edit_column("city", lambda x: x.upper() if x else x)
print(frame.to_dicts())

# Drop score column
frame.drop_columns(["score"])
print(frame.to_dicts())

# Rename name column
frame.rename_column("name", "full_name")
print(frame.to_dicts())

# Group by city
groupby = ft.TinyGroupBy(frame, keys=["city"])
print(groupby.key_list)
print(groupby.group_map)

# Count per group
count_frame = groupby.count(frame)
print(count_frame.to_dicts())

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⚙️ Supported Types

Type	Column variant
int	Int, OptInt
float	Float, OptFloat
bool	Bool, OptBool
str	Str, OptStr
mixed	Mixed, OptMixed

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🐉 Why "feathertail"?

In Fourth Wing, "feathertail" refers to a juvenile stage of dragons — smaller, golden, and known for their feathery tails rather than weaponized ones. Feathertail dragons, like Andarna, are characterized by gentleness, non-violence, and an elegant simplicity.

This library embodies those same principles: lightweight, non-destructive, and focused on providing clean, powerful tools for data transformation without heavy dependencies or unnecessary complexity.

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❤️ Contributing

Contributions and ideas are always welcome! Open an issue or a pull request.

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📄 License

MIT