For various reasons I don't really like black even if it's very good at what it does.

The readability of a Django model with aligned fields vs after running black is a good example of why I'd never use it by default.

Anyhow…

It would be nice to use black occasionally on snippets of code from inside my editor (vim) but that almost never works as the first line is already indented.

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I thought I understood async programming as I'd written a few non-trivial apps in the past (using Boost ASIO)

Who has two thumbs and suffers from async programming Dunning-Kruger effect? This guy!

So here's the first of hopefully many recipes to make async programming under Python 3.6 a little easier.

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You should always use the logging module instead of just littering print statements all over your code. You will very quickly thank yourself for taking a bit of extra time.

Having said that, setting up logging is a bit of a pain so here's the pattern I use 90% of the time.

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Uploading to Minio (or S3) in a script is a bit tricky.

Update: now on GitHub with some Python versions.

#!/bin/bash

# usage: ./minio-upload my-bucket my-file.zip

bucket=$1
file=$2

host=minio.example.com
s3_key='secret key'
s3_secret='secret token'

resource="/${bucket}/${file}"
content_type="application/octet-stream"
date=`date -R`
_signature="PUT\n\n${content_type}\n${date}\n${resource}"
signature=`echo -en ${_signature} | openssl sha1 -hmac ${s3_secret} -binary | base64`

curl -v -X PUT -T "${file}" \
          -H "Host: $host" \
          -H "Date: ${date}" \
          -H "Content-Type: ${content_type}" \
          -H "Authorization: AWS ${s3_key}:${signature}" \
          https://$host${resource}

Alkali v0.5.5 has now escaped.

Code at github.com and docs at readthedocs.org.

Major features are:

• adding BoolField
• adding CSVStorage, load/save csv files
• queries are bit more efficient/fast, don't copy as many objects by default
• some doc cleanups

You can now nicely render markdown in your console/terminal with ConsoleMD in glorious color.

Note the subtlety changing hues of the subtopics, the brilliance of auto-incrementing list counters, the dulcet notes of the embedded python, the elegant italics of the block quote. ConsoleMD has it all! At least with regards to my small test files.

Code is on github.com

Alkali v0.5.4 has now escaped.

Code at github.com and docs at readthedocs.org.

Major features are:

• implemented Query.distinct
• implemented Query.annotate
• implemented Query.aggregate functions: Sum, Count, Min, Max
• Fields are now descriptors on Model instance
• added ForeignKey field
• models now cascade delete when ForeignKey instance is deleted
• minor speed ups
• IntField now has auto_increment property
• Query returns copies of Model instances
• added signals on model creation/deleting/saving/etc
• better documentation

I had a hell of a time trying to make a nice help command while using click.

I wanted the ability to have a help sub-command for each real command.

mycommand --help
mycommand help

mycommand foo --help
mycommand help foo

It's actually fairly easy (once you know how).

CTX_SETTINGS=dict(help_option_names=['-h','--help'])

@click.group(context_settings=CTX_SETTINGS)
@click.pass_context
def cli(ctx, **kw):
    ...

@cli.command()
@click.pass_context
def foo(ctx):
    ...

@cli.command()
@click.argument('topic', default=None, required=False, nargs=1 )
@click.pass_context
def help(ctx, topic, **kw):
    if topic is None:
        print ctx.parent.get_help()
    else:
        print cli.commands[topic].get_help(ctx)

Packages change pretty frequently when you're using Homebrew on OSX, including Python.

I noticed that I had several instances of lots of large packages installed (Boot, MacVim, Python, etc) so I ran brew cleanup and that freed up approx 9 gigs of disk! Unfortunately it also broke many virtual environments since the version of python that they were pointing at no longer existed.

What to do what to do…

Based on this Stack Overflow question I wrote a script to update a single virtual environment or all of them.

Note, this only updates virtual enviroments created with virtualenvwrapper. Also, you may have to reinstall your packages, but hopefully not.

#!/bin/bash

if [ -z "$1" ]; then
    echo "usage: $0 virtualenv|all"
    exit 1
fi

if [ -z "$WORKON_HOME" ]; then
    echo "you must export WORKON_HOME"
    exit 1
fi

if [ "$1" = "all" ]; then
    echo "udpating all virtualenvs"
    cd $WORKON_HOME

    for name in $(find . -type d -maxdepth 1 -mindepth 1|xargs -n1 basename); do
        $0 $name
    done

    exit 0
fi

cd $WORKON_HOME
virtenv="$WORKON_HOME/$1"

echo "deleteing $1"

rm -f  $virtenv/.Python
rm -f  $virtenv/bin/pip
rm -f  $virtenv/bin/pip2
rm -f  $virtenv/bin/pip2.7
rm -f  $virtenv/bin/python
rm -f  $virtenv/bin/python2
rm -f  $virtenv/bin/python2.7
rm -fr $virtenv/include
rm -f  $virtenv/lib/python2.7/* 2> /dev/null
rm -fr $virtenv/lib/python2.7/distutils
rm -f  $virtenv/lib/python2.7/site-packages/easy_install.*
rm -fr $virtenv/lib/python2.7/site-packages/pip
rm -fr $virtenv/lib/python2.7/site-packages/pip-*.dist-info
rm -fr $virtenv/lib/python2.7/site-packages/setuptools
rm -fr $virtenv/lib/python2.7/site-packages/setuptools-*.dist-info

source `which virtualenvwrapper.sh`

echo "creating $1"
mkvirtualenv -q $1

There are dozens of similar programs on the the ol' internetz and here's mine.

I'm not a cryptographer.

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