Bottle Plugin Lifecycle

If you use Python‘s Bottle micro-framework there’ll be a time where you’ll want to add custom plugins. To get a better feeling on what code gets executed when, I created a minimal Bottle app with a test plugin that logs what code gets executed. I uesed it to test both global and route-specific plugins.

When Python loads the module you’ll see that the plugins’ __init__()  and setup()  methods will be called immediately when they are installed on the app or applied to the route. This happens in the order they appear in the code. Then the app is started.

The first time a route is called Bottle executes the plugins’ apply()  methods. This happens in “reversed order” of installation (which makes sense for a nested callback chain). This means first the route-specific plugins get applied then the global ones. Their result is cached, i.e. only the inner/wrapped function is executed from here on out.

Then for every request the apply()  method’s inner function is executed. This happens in the “original” order again.

Below you can see the code and example logs for two requests. You can also clone the Gist and do your own experiments.

Android Backup and Restore with ADB

Updating my OnePlus One recently to Cyanogen OS 12 I had to reset my phone a few times before everything ran smoothly … so I wrote a pair of scripts to help me copy things around.

It uses the Android SDK’s ADB tool to do the copying since the Android File Transfer Tool for Mac has a laughable quality for Google’s standards.

Synchronize directories between computers using rsync (and SSH)

https://twitter.com/climagic/status/363326283922419712

I found this command line magic gem some time ago and was using it ever since.

I started using it for synchronizing directories between computers on the same network. But it felt kind of clunky and cumbersome to get the slashes right so that it wouldn’t nest those directories and copy everything. Since both source and destination machine had the same basic directory layout, I thought ‘why not make it easier?’ … e.g. like this:

It uses rsync for the heavy lifting but does the tedious source and destination mangling for you. 😀

You can find the code in this Gist.

MagicDict

If you write software in Python you come to a point where you are testing a piece of code that expects a more or less elaborate dictionary as an argument to a function. As a good software developer we want that code properly tested but we want to use minimal fixtures to accomplish that.

So, I was looking for something that behaves like a dictionary, that you can give explicit return values for specific keys and that will give you some sort of a “default” return value when you try to access an “unknown” item (I don’t care what as long as there is no Exception raised (e.g. KeyError )).

My first thought was “why not use MagicMock?” … it’s a useful tool in so many situations.

But using MagicMock where dict is expected yields unexpected results.

First of all attribute and item access are treated differently. You setup MagicMock using key word arguments (i.e. “dict syntax”), but have to use attributes (i.e. “object syntax”) to access them.

Then I thought to yourself “why not mess with the magic methods?” __getitem__  and  __getattr__  expect the same arguments anyway. So this should work:

Well? …

… No!

By this time I thought “I can’t be the first to need this” and started searching in the docs and sure enough they provide an example for this case.

Does it work? …

Well, yes and no. It works as long as you only access those items that you have defined to be in the dictionary. If you try to access any “unknown” item you get a KeyError .

After trying out different things the simplest answer to accomplish what I set out to do seems to be sub-classing defaultdict.

And? …

Indeed, it is. 😀

Well, not quite. There are still a few comfort features missing (e.g. a proper __repr__ ). The whole, improved and tested code can be found in this Gist:

Google Has Most of My Email Because It Has All of Yours

Benjamin Mako Hill has followed up on an interesting thought: in a world where many people use Gmail, just how many of your daily emails also land on Google’s servers even if you aren’t using their services? … For him it turns out more than 50%. o.O

Unsafe Chrome Sometimes Necessary

In my work – every now and then – I found myself in need of a browser with reduced security checks (mainly to gloss over cross domain XMLHttpRequests and SSL certificate violations) for testing purposes. I didn’t want to take the risk and use my main browser session with these settings, so I made me a script (also available as a Gist). 🙂

Tip:
If you use oh my ZSH you can save this file in ~/.oh-my-zsh/custom/plugins/chrome-unsafe/chrome-unsafe.plugin.zsh and add “chrome-unsafe” to your list of used plugins in ~/.zshrc