Posts tagged: pydantic

I came accross from_attributes today it allows creation of pydantic models from objects such as a sqlalchemy Base Model or while nesting pydantic models. I believe in the past I have ran into some inconsistencies with nesting pydantic models and I’ll bet one had from_attributes set and another did not.

Arbitrary class instances¶ (Formerly known as “ORM Mode”/from_orm).

Pydantic models can also be created from arbitrary class instances by reading the instance > attributes corresponding to the model field names. One common application of this functionality is integration with object-relational mappings (ORMs).

To do this, set the from_attributes config value to True (see the documentation on Configuration for more details).

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exclude=True and repr=False is a good pydantic combination for secret attributes such as user passwords, or hashed passwords. exclude keeps it out of model_dumps, and repr keeps it out of the logs.

I went down the route of leveraging the json-enc extention in htmx, but later realized that this completely breaks browsers/users who do not wish to use javascript. While most of the web would feel quite broken with javascript disabled, I don’t want to contribute to that without good reason.

Taking a second look into this issue, rather than using json-enc, and using as_form to get form data into a model keeps the nice DX fo everything being a pydantic model, but the site still works without js. with js htmx kicks in, you get a spa like experience by loading partials onto the page, and without, you just get a full page reload.

copied from August 8, 2023

global Field global BaseModel from pydantic import BaseModel from pydantic import Field

Pydantic is a Python library for serializing data into models that can be validated with a deep set of built in valitators or your own custom validators, and deserialize back to JSON or dictionary.

To install pydantic you will first need python and pip. Once you have pip installed you can install pydantic with pip.

pip install pydantic

Always install in a virtual environment

To get started with pydantic you will first need to create a Pydantic model. This is a python class that inherits from pydantic.BaseModel.

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