Nick Khitrov nkhitrov

This Stub class is designed as a workaround for Fastapi Depends which mixes IoC-Container features with request parsing.

You can use parametrized Stub instance to declare dependency whilst not show your class'es __init__ params in OpenAPI specification.

Python People

(Updated 2022-11-16 with suggestions from comments below, Twitter and Mastodon)

An incomplete list of people in the Python community to follow on Twitter and Mastodon.

With the risk that Twitter dies, I'd be sad to lose links to interesting people in the community, hence this list.

I would love you to comment below with links to people I've missed.

Logging setup for FastAPI

This logging setup configures Structlog to output pretty logs in development, and JSON log lines in production.

Then, you can use Structlog loggers or standard logging loggers, and they both will be processed by the Structlog pipeline (see the hello() endpoint for reference). That way any log generated by your dependencies will also be processed and enriched, even if they know nothing about Structlog!

Requests are assigned a correlation ID with the asgi-correlation-id middleware (either captured from incoming request or generated on the fly). All logs are linked to the correlation ID, and to the Datadog trace/span if instrumented. This data "global to the request" is stored in context vars, and automatically added to all logs produced during the request thanks to Structlog. You can add to these "global local variables" at any point in an endpoint with `structlog.contextvars.bind_contextvars(custom

Migrating from Ubuntu on WSL to ArchLinux on WSL2

Obsolete notice

This document was created back in 2020 and might not be actual nowadays. It is not supported anymore, so use thise information at your own risk.

Upgrading to WSL 2

Download WSL2 Kernel
run wsl --set-default-version 2 in windows command line, so that all future WSL machine will use WSL2.

Renaming table in Ecto migration

I recently wanted to rename a model and its postgres table in a Phoenix app. Renaming the table was simple and documented, but the table also had constraints, sequences, and indexes that needed to be updated in order for the Ecto model to be able to rely on default naming conventions. I couldn't find any examples of what this would look like but was eventually able to figure it out. For anyone else in the same situation, hopefully this example helps.

In the example below, I'm renaming the Permission model to Membership. This model belongs to a User and an Account, so it has foreign key constraints that need to be renamed.

defmodule MyApp.Repo.Migrations.RenamePermissionsToMemberships do
  use Ecto.Migration

Virtualenv on WSL with ZSH

Install PIP

sudo apt install python-pip
sudo apt install python3-pip

pip --version
pip3 --version

Нагрузочное тестирование c Yandex.Tank и JMeter

На этой странице описывается процесс настройки нагрузочного тестирования внешних ресурсов.

Кратко

Для тестирования поведения сервиса под нагрузкой используется утилита Yandex Tank.

Танку можно указать патроны (HTTP-запросы, которые будут отправлены на целевой сервер) и расписание (количество запросов в секунду к целевому серверу в каждый момент времени стрельб, а также продолжительность стрельб). Также к танку можно подключить плагин мониторинга, позволяющий снимать показатели (например, количество свободной памяти или загрузку процессора) с целевого сервера.

How do I round to 2 decimals?

In python, you have floats and decimals that can be rounded. If you care about the accuracy of rounding, use decimal type. If you use floats, you will have issues with accuracy.

All the examples use demical types, except for the original value, which is automatically casted as a float.

To set the context of what we are working with, let's start with an original value.

	import gc
	import time
	from collections import defaultdict

	import attrs
	from opentelemetry import metrics
	from opentelemetry.metrics import CallbackOptions, Observation


	@attrs.define

	from typing import Optional
	import base64
	from passlib.context import CryptContext
	from datetime import datetime, timedelta

	import jwt
	from jwt import PyJWTError

	from pydantic import BaseModel