zzzeek

"""Proof of concept of an adapter that will wrap a blocking IO library in
greenlets, so that it can be invoked by asyncio code and itself make calls out
to an asyncio database library.

hint:  any Python ORM or database abstraction tool written against the DBAPI
could in theory allow asyncio round trips to a pure async DB driver like
asyncpg.

The approach here seems too simple to be true and I did not expect it to
collapse down to something this minimal, so it is very possible I am totally

zzzeek

"""This is a simpler version of the greenlet
example at https://gist.github.com/zzzeek/4e89ce6226826e7a8df13e1b573ad354

Instead of the "await" keyword, we use the "await_()" function to interact with
the greenlet context. the greenlet context itself is 23 lines of code right
here.

"""

import asyncio

zzzeek

""" "Writing SQL is just as fast as using an ORM" proof of concept

Below is a simple Python object model, where we represent a database that
stores the names of employees at a company, some of whom are "engineers",
and a list of the jobs they do and the programming languages they use.

We'd like to persist the state represented by this Python object model
in a relational database, using our Python objects as a start.  Then we'd
like to write SQL queries for rows in this database, and we get back instances
of Python objects exactly as they were created.

zzzeek

"""This program is exactly the same as that of

https://gist.github.com/zzzeek/33943060f7a08cf9e82bf8df1f0f75de ,
with the exception that the add_and_select_data function is written in
synchronous style.

UPDATED!!   now includes refinements by @snaury and @Caselit .  SIMPLER
AND FASTER!!

zzzeek

from __future__ import annotations

from typing import TYPE_CHECKING

import pydantic.dataclasses

from sqlalchemy import Column
from sqlalchemy import create_engine
from sqlalchemy import ForeignKey
from sqlalchemy import Integer

zzzeek

#!/usr/bin/env bash


# notes:
# tuning camera:  gtk-v4l package, v4l2-ctl
# we also have:
# ffmpeg, mpg123

# linux
#RESOLUTION="640x480"

zzzeek

This is a cross post of something I just posted on the Python bug tracker at https://bugs.python.org/msg373145.

I seem to have two cents to offer so here it is. An obscure issue in the Python bug tracker is probably not the right place for this so consider this as an early draft of something that maybe I'll talk about more elsewhere.

> This basically divides code into two islands - async and non-async

zzzeek

from sqlalchemy.testing.profiling import profiled
from sqlalchemy import create_engine
from sqlalchemy import event


engine = create_engine('oracle://scott:tiger@localhost/xe')

# disregard all output type handling - Python unicodes
# will no longer be supported
@event.listens_for(engine, "connect")

zzzeek

# So interestingly, Signature seems to be twice as fast in Python 3.6 and 3.7 as it 
# was in Python 3.3 and 3.4.  However, it is still 6-18 times slower than the old
# getargspec or getfullargspec that was in Python 3.3.

Python 2.7 getargspec (doesn't use Signature)         : specimen_one (6 args)   : 0.0503
Python 2.7 getargspec (doesn't use Signature)         : specimen_two (0 args)   : 0.0496
Python 2.7 getargspec (doesn't use Signature)         : specimen_three (6 args) : 0.0500
Python 2.7 getargspec (doesn't use Signature)         : specimen_four (13 args) : 0.0652

Python 3.3 getfullargspec (doesn't use Signature)     : specimen_one (6 args)   : 0.0539

zzzeek

import threading

def one(obj):
    while True:
        skip = set()
        try:
            {k: v for k, v in obj.__dict__.items() if k not in skip}
        except RuntimeError as err:
            print("%s" % err)