Import: Pydantic Model

Creates a data contract from Pydantic model classes, the counterpart to datacontract export pydantic-model.

The module is read statically with Python's ast, never imported, so a contract can be derived from a service's models without installing that service's dependencies or executing any of its code.

Module-level models become schema objects, except those used as the type of another model's field: those are inlined as nested objects. Field(...) constraints become logicalTypeOptions, and Literal types and Enum classes become an invalidValues quality rule listing the valid values.

Given this orders.py:

import datetime
from enum import Enum
from typing import Optional

from pydantic import BaseModel, Field


class Status(str, Enum):
    PENDING = "pending"
    SHIPPED = "shipped"
    DELIVERED = "delivered"


class Orders(BaseModel):
    """One row per customer order."""

    order_id: str = Field(max_length=32)
    order_timestamp: datetime.datetime
    customer_id: Optional[str] = None
    order_total: int = Field(description="Order total in cents.", ge=0)
    status: Status

Run:

datacontract import pydantic-model --source orders.py

to produce the data contract:

version: 1.0.0
kind: DataContract
apiVersion: v3.1.0
id: my-data-contract
name: My Data Contract
status: draft
schema:
- name: Orders
  physicalType: object
  description: One row per customer order.
  logicalType: object
  physicalName: Orders
  properties:
  - name: order_id
    physicalType: str
    logicalType: string
    logicalTypeOptions:
      maxLength: 32
    required: true
  - name: order_timestamp
    physicalType: datetime
    logicalType: timestamp
    required: true
  - name: customer_id
    physicalType: str
    logicalType: string
    required: false
  - name: order_total
    physicalType: int
    description: Order total in cents.
    logicalType: integer
    logicalTypeOptions:
      minimum: 0
    required: true
# …

All options: datacontract import pydantic-model.