Things in Django I constantly forget

There are some things in Django I constantly forget!

Getting the friendly value for a enum value

You have model:

class MyModel(models.Model)
    thing = models.IntegerField(choices=SOME_CHOICES)

You want the value for thing:
happy_value = my_instance.get_thing_valuedisplay()

Use the free jupyter shell that comes with django extensions

pip3 install jupyter
or
python -m pip install jupyter
then
python manage.py shell_plus --notebook

MySQL - create database and user quickly

I'm not a MySQL fan. I don't use it enough to remember some basic things.

mysql> create database mydb;

mysql> create user 'myuser'@'localhost' IDENTIFIED BY '*******';

mysql> grant all privileges on mydb.* to 'myuser'@'localhost';

Things about python that I constantly forget (hate)

SyntaxError: Non-ASCII character '\xe2' in file blah.py on line 67, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

Gaaaaah!

Put at top of file:

# -*- coding: utf-8 -*-

Why I love Python

Reason #1

monkeys.sort(key=lambda monkey: monkey.height)

Reason #1.2

monkeys.sort(key=lambda monkey: (monkey.height, monkey.age))

Reason #1.3

monkeys.sort(key=lambda monkey: (monkey.height, monkey.age), reverse=True)

log4net

I keep forgetting how to switch on log4net (using app.config)

I always end up wasting time on the apache docs, and searching the net to find this

Step 0:

Ensure that the first declaration of

"private static readonly log4net.ILog Log =log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);"

Occurs in your main assembly - if the first declaration is in linked assemblies, it won't load the setting correctly.

Step 1: Edit AssemblyInfo.cs
[assembly: log4net.Config.XmlConfigurator(Watch = true)]

Step 2: Edit App.config

Important! The configSections bit has to be at the top of your config file. So if you've got an existing one, don't just add it on to the end!

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<log4net>
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender" >
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%ndc] - %message%newline" />
</layout>
</appender>
<root>
<level value="INFO" />
<appender-ref ref="ConsoleAppender" />
</root>
</log4net>
</configuration>

Step 3:

Need more example files - go to http://logging.apache.org/log4net/release/config-examples.html