E pur si muove
River is a tiling Wayland compositor, a thing previously known as a window manager. The unique feature is that is uses tags to organise windows, rather than workspaces. It's been my window manager of choice ever since a buggy X.org driver that was never going to be fixed forced …
Cross posted from https://www.iroh.computer/blog/closing-a-quic-connection QUIC is a great transport protocol, and a very good choice in today's internet. I'm not going into too much detail here, there are plenty of explanations about what the benefits of QUIC are. Closing a QUIC connection without losing any …
Knowing almost nothing about frontend development or GIS I wanted to be able to display something on a map on my own computer (desktop). Knowing a fair bit of Rust but not having a clue about anything else involved I decided the easiest way to do this was probably to …
Introduction On the surface of it the Linux socket API is pretty straight forward. However once you start to care about performance things get a bit more complicated, and documentation a bit more sparse. Because I thought it'd be fun to explore this a bit more I made a simple …
Background The primary way I use email is through notmuch and notmuch-emacs on my laptop, which reads email from a local maildir . Sending mail is done using the venerable sendmail(8) command, which is backed by nullmailer to send it out via SMTP to the relay server of my email …
I've recently set up another laptop with whith whole-disk encryption, including /boot . This is all fine --the debian-installer almost gets it right, you just need to edit /etc/default/grub to add GRUB_ENABLE_CRYPTODISK=y and then re-run grub-install on the target-- but once you get this working you end up …
This post is a response to A Container Is A Function Call by Glyph. It is a good article and worth your time reading, and you might want to read it to follow here. On twitter I asserted the article recommends building a monolith while Glyph countered "On the contrary …
Testing is a really important part of Python development and picking the testing tool of choice is no light decision. Quite a few years ago I eventually decided py.test would be the best tool for this, a choice I have never regretted but has rather been re-enforced ever since …
Python links the module namespace directly to the layout of the source locations on the filesystem. And this is mostly fine, certainly for applications. For libraries sometimes one might want to control the toplevel namespace or API more tightly. This also is mostly fine as one can just use private …
At long last I have updated my pytest-timeout plugin. pytest-timeout is a plugin to py.test which will interrupt tests which are taking longer then a set time and dump the stack traces of all threads. This was initially developed in order to debug some some tests which would occasionally …
The general advice for handling text in an application is to use a so called unicode sandwich : that is decode bytes to unicode (text) as soon as receiving it, have everything internally handle unicode and then right at the boundary encode it back to bytes. Typically the boundaries where the …
It appears there is some arguments against putting copyright statements on the top of a file in free software or open source projects. Over at opensource.com Rich Bowen argues that it is counter productive and not in the community spirit (in this case talking about OpenStack). It seems to …
Solaris is one of those things which tends to be a bit un-loved, it being baught by Oracle probably didn't help either. But regardless they've made a rather nice and modern OS out of it and it is used in a fair few places so you may need to support …
or Skipping modules in py.test using marks but no importing As I've said before, py.test is my favourite testing tool. One if it's features is that it allows you to mark tests with arbitrary "marks" , built in ones are e.g. skipif , xfail etc. But py.test's extension …
Today I've spent a few minutes tweaking Emacs a little. The result is very simple yet makes a decent impact on usage. Firstly I remembered using the c-subword-mode a long time ago, I couldn't believe I never used that in Python. Turns out there is a more genericly named subword-mode …
Today I wasted a lot of time trying to figure out why a class using both a __getattr__ and a property mysteriously failed. The short version is: Make sure you don't raise an AttributeError in the property.fget() The start point of this horrible voyage was a class which looked …
Eventlet is an asynchronous network I/O framework which combines an event loop with greenlet based coroutines to provide a familiar blocking-like API to the developer. One of the reasons I like eventlet a lot is that the technology it builds on allows it's event loop to run inside a …
Solaris 10 introduced "contracts" for processes. You can read all about it in the contract(4) manpage but simply put it's a grouping of processes under another ID, and you can "monitor" these groups, e.g. be notified when a process in a group coredumps etc. This is actually one …
This is a counter-intuitive discovery, in IPython : In [ 18 ]: expr = re . compile ( 'foo' ) In [ 19 ]: % timeit expr.search('foobar') 1000000 loops , best of 3 : 453 ns per loop In [ 20 ]: % timeit expr.match('foobar') 1000000 loops , best of 3 : 638 ns per loop So now I'm left wondering why .match …
When using an SQLite in-memory databases in storm the different stores created from the same database are not modifying the same SQLite database. E.g. db = storm . locals . create_database ( 'sqlite:' ) store1 = storm . locals . Store ( db ) store2 = storm . locals . Store ( db ) Here store1 and store2 will not refer to the same …
So I've got a multi-threaded application and suddenly I notice there's one thread running away and using all CPU. Not good, probably a loop gone wrong. But where? One way to find this is revert history in the VCS and keep trying it out till you find the bad commit …
Somehow my brain seems to think there's a reason not to return inside a with statement, so rather then doing this: def foo (): with ctx_manager : return bar () I always do: def foo (): with ctx_manager : result = bar () return result No idea why nor where I think to have heard/read this …
I am a great proponent of the python standard library , I love having lots of tools in there and hate having to resort to thirdparty libs. This is why I was wondering if there could be a real templating engine in the stdlib some day? I'm not a great user …
Searching the svn-buildpackage manpage for the 3.0 (quilt) format I thought that it wasn't able to apply the patches in debian/patches during build time. Instead I was doing a horrible dance which looked something like svn-buildpackage --svn-export; cd ../build-area/...; debuild . Turns out I was completely wrong. svn-buildpackage doesn't …
I use threads correctly I do not use virtualenv and dont't want to Just needed to get that out of my system after europython, now mock me. PS: I should probably have done this as a lightening talk but that occurred to me too late.
Recently I've been enjoying py.test 's test function arguments , it takes a little getting used too but soon you find that it's quite likely a better way then the xUnit-style of setup/teardown. One slightly more advanced usage was using cached setup together with test generators however. While not …
Sometimes you'd want to use something like select.select() on Queues . If you do some searching for this it turns out that this question has been answered for multiprocessing Queues where you can simply use the real select on the underlying socket (IIRC), but for a good old fashioned Queue …
While Python has a garbage collector pretty much whenever circular references are touched upon it is advised to use weak references or otherwise break the cycle. But should we really care? I'd like not to, it seem like something the platfrom (python vm) should just provide for me. Are all …
There is sometimes a need to set the process name from within python, this would allow you to use something like pkill myapp rather then the process name of your application just being yet another "python". Bugs (which I'm now failing to find in Python's tracker) have been filed about …
The Storm ORM struggles with sqlite3's <http://docs.python.org/library/sqlite3.html> transaction behaviour as they explain in their source code. Looking at the implementation of .raw_execute() the side effect of their solution to this is that they start an explicit transaction on every statement that gets executed. Including …
Here's something that surprised me: a = None def f (): b = a return b def g (): b = a a = 'foo' return b While f() is perfectly fine, g() raises an UnboundLocalError . This is because Python optimises access to local variables using the LOAD_FAST/STORE_FAST opcode, you can easily see why this …
Recently I"ve been messing around with python bytecode, as a result I now know approximately how the python virtual virtual machine works at a bytecode level. I've found this quite interesting but other then satisfying my own curiosity had no benefit from this knowledge. Until today I was wondering …
Mock is a great module to use in testing, I use it pretty much all the time. But one thing I have nerver felt great about is the syntax of it's call_args (and call_args_list ): it is a 2-tuple of the positional arguments and the keyword arguments, e.g. (('arg1', 'arg2' …
It seems that many people think you need distribute if you want to run 2to3 automatically in your setup.py . But personally I don't like setuptools (aka distribute) and hence don't like forcing this on users. No worries since plain old distutils supports this as well, but it simply appears …
This may seem simple and trivial, but today I discovered the basestring type in Python. It is essentially a base type for str and unicode , which comes in handy when writing isinstance(foo, basestring) in test code for example. Strangely, despide PEP 237 mentioning the equivalent for int and long …
When you have someplace where you register a set of callbacks you have a few options: Use an interface-style API. I.e. you have a Mixin style class defining the methods expected to be present, probably just raising NotImplementedError . You then just pass in the entire object to the .register …
Pointer arithmetic in C is great. The only downside is that it's only defined when pointing to an array (or an item just after the array). That is one giant downside. Allocate a chunk of memory and you can't use pointer arithmetic. So if you are building a linked list …
Catherine Devlin describes it very nicely : I finally understand Al-Qaeda's master plan, and it's freaking brilliant . [...] I'm just surprised that we're choosing to participate in the plan. I thought we were on opposite sides?
Why was it ever considered desirable to call a directory containing a __init__.py file a "package" rather then just "module". They are after all simply "modules containing other modules". It's not like that solved some sort of problem was it? But, as sad as that sometimes might be, we …
Most important thing first: the eLOM console lives on ttyS1 (9600n8) . If that gets you going you do not need to read any more. This works pretty easily, but there's isn't much information about how this works if you don't like using a keyboard and a screen (having these things …
My gut tells me it's horribly wrong but I am failing to formulate a decent argument, let me show an example what I mean (somewhat contrived): def deco ( f ): def wrapper ( self , * args , ** kw ): with self . lock : f ( self , * args , ** kw ) class Foo : def __init__ ( self ): self . lock = threading . Lock …
So Windows has this strange thing called COM . It allows you to share objects between unrelated processes and languages, a bit like CORBA in that sense, only very different. Anyway, if you'd like to get information out of this other Windows thing called WMI (which provides a lot of information …
This counts for one of the more crazy things I'd like to do with Python: insert an instance of a descriptor object into the class dict of a module. While you can get hold of the module type class by using the __class__ attribute of any module or use types …
If you got a test suite that runs some very slow tests it might be troublesome to run those all the time. There is of course the "-k" option to py.test which allows you to selectively enable only a few tests. But what I really wanted was a way …
Reinout van Rees : In case you heard of both setuptools and distribute: distribute fully replaces setuptools. Just use distribute. Setuptools is “maintained” (for various historically dubious values of “maintain”) by one person (whom all should applaud for creating the darn thing in the first place, btw!). Distribute is maintained by …
innovative company noun 1 a company which can't afford patent lawyers *2 one of the lucky handful companies who are innovative and have money for patent lawyers *HELP Not to be confused with most companies lobying in patent litigation. PS: It's also possible to have companies that can't afford patent …
If you are driving on a motorway where I am driving too, here are some rules you should follow. I think you should even follow them when I'm not around. Be sensible, this one overrules all the others Keep left unless overtaking KEEP LEFT UNLESS OVERTAKING KEEP LEFT UNLESS OVERTAKING …
Because it's easier then buying one When connecting two computes together (e.g. your laptop to a server or router) to get access to a console you need to use a crosslinked RS-232 cable, usually with two female DE-9 connectors these days. This cable is more commonly known as a …
Do not, I repeat, do not define .__getstate__() idly. Thank you very much
Todays pleasant surprise: >>> a = { 'a' : ( 0 , 1 ), 'b' : ( 2 , 3 )} >>> for k , ( v1 , v2 ) in a . iteritems (): ... print k , v1 , v2 ... a 0 1 b 2 3 >>> Nice!