poldantic 0.1.0

Convert Pydantic models to Polars schemas

🧩 Poldantic

Poldantic converts Pydantic models into Polars schemas — making it easy to validate, align, and document your data pipeline types between the Python and Polars worlds.

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✨ Features

• 🔁 Convert BaseModel classes to polars.Schema or pl.Struct
• ✅ Handles optional fields (Optional[T]) and union types
• 🧱 Supports nested and deeply nested Pydantic models
• 📦 Outputs multiple formats: dict, list, pl.Schema, pl.Struct
• 🧠 Tracks nullable status via FieldInfo

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📦 Installation

pip install poldantic

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🚀 Usage

from pydantic import BaseModel
from typing import Optional, List
import polars as pl
import poldantic as pd

class Address(BaseModel):
    street: str
    zip: Optional[int]

class User(BaseModel):
    id: int
    name: str
    address: Address
    tags: List[str]

pd.get_polars_schema_dict(User)
# {'id': pl.Int64, 'name': pl.Utf8, 'address': pl.Struct([...]), 'tags': pl.List(pl.Utf8)}

pd.get_polars_schema(User)
# pl.Schema({...})

pd.get_polars_struct(User)
# pl.Struct([...])

pd.get_polars_fieldinfo_dict(User)
# {'name': FieldInfo(dtype=Utf8, nullable=False), ...}

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🧪 Output Formats

Function	Output
get_polars_schema_dict()	dict[str, pl.DataType]
get_polars_schema_list()	list[(str, pl.DataType)]
get_polars_fieldinfo_dict()	dict[str, FieldInfo]
get_polars_fieldinfo_list()	list[(str, FieldInfo)]
get_polars_schema()	pl.Schema
get_polars_struct()	pl.Struct

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🔍 FieldInfo

The FieldInfo object tracks both the Polars data type and its nullability:

@dataclass
class FieldInfo:
    dtype: pl.DataType
    nullable: bool = False

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📚 Examples

See examples/poldantic_demo.ipynb for a working notebook showing nested models and schema inspection.

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📜 License

MIT License © 2025 Odos Matthews