Semi-technical thoughts

It often happens that you need to echo or cat something to some config file, or maybe a log, or something else owned by root. It also often happens that you try to run it as a regular user and get a permission denied error. And normally you'd just prepend your command with sudo and be done with it, but output redirects are not that easy: current shell will handle them itself, they will not be passed to sudo and you will still have your permission problem. Luckily, the fix is easy: instead of prepending the command, you just replace > somefile with | sudo tee somefile and >> somefile with | sudo tee -a somefile  whatever the command before was. You may also add > /dev/null if you don't want if to echo everything. Example: echo "truncated" | sudo tee /var/log/toolong.log echo "additional log record" | sudo tee -a /var/log/toolong.log Of course, this is not the only way and it's not always the best but it works all the time, it...

Ok, so I've bought a new gadget. It was long overdue because I, being a MediaPad X1 user, sometimes feel uncomfortable pulling that monster of a phone just to check the time on answer a call. Of course, Bluetooth headsets are cheap and abundant but I don't really like the idea of keeping one in my ear all the time. And having it not in the ear usually makes it pretty much unusable. Various wearable gdgets that can show time and some notifications aren't new either, and there are a lot of cheap options, but, again, there are even cheaper watches and I don't care much about fitness tracking (I don't mind it though) and notifications (reading long texts is seldom convenient on a small screen anyway). So when I heard about the new TalkBand that combines watch and wireless headset I was all interested, read reviews, became even more interested, and waited a few weeks only because of the price and availability. The price, for most people around the world it might seem a...

As some of you know, I'm a happy owner of Huawei Mediapad X1. So far it's the best 7" phablet (not counting the new Mediapad X2, obviously, which has better hardware with the same size and slightly changed buttons) but this post is not about device itself, instead I wanted to write a few words about cables, cases, screen protectors available on the market. By "market" I usually mean Aliexpress but some stuff might be available in your local stores as well. I'm not endorsing any sellers or brands, especially not original accessories, and prices are for reference only (and usually are for one piece and include shipping i.e. if you're thinking to buy a dozen of something, you might be able to find a better deal). In almost all the cases there might be cheaper options but with worse quality, seasonal deals and everything tend to change every month as new manufacturers and sellers come to market. Unlike competitors' devices in the same form factor (I...

There are quite a few ways you can format a multi-line function call/list/dictionary in a programming language. With Python (at least with PEP8) it's just two ways: hanging indentation and vertical indentation. The latter is quite straight-forward and I mention it in the notes below. The former one is what this post is about. Well, about a minor but important question of where to place the closing bracket when using it. Yes, style is much more than formatting the commas and brackets so let's settle this and move on to the more important questions. When using hanging indentation, the only true way is this one(*): some_tuple = ( # Nothing here, only opening bracket. item1, item2, item3, item4, # Several items on one line is acceptable though not recommended. item5, # Last comma is important. And never, never place the closing bracket here. ) # Again, nothing here but the bracket and it's on the same level as the opening line. Empty line after the o...

Many companies these days are starting using Docker in their workflow, both big shots and tiny startups, even open-source projects which might sometimes be somewhat conservative when it comes to tools. I'm not trying to provide any kind of instruction here but instead to ask questions you should be asking yourself before following or not following their lead. I'm concentrating on context of web services using Django and Python, but it should be applicable to more or less anything. I must admit that Docker is cool. Linux containers is a fascinating thing itself and Docker is a great tool for simplifying their use for whatever purpose. Reusable and simple to build and share images, an easy way to launch those images and do stuff with them is a must if you use them. But should you containerize everything? It might, on the other hand, over-complicate your process without any significant benefits. So the first question is: do you even need containers or would you better off withou...

Every developer knows  datetime.strftime()  method, but some don't know that its argument's format is not documented in full in the official documentation. For example, you won't find any mention of %s directive there which means UNIX epoch time, timestamp. It works (at least with every major version of Python on Linux, FreeBSD, and MacOS), I've tested it a few times myself, it's just not documented. I recently saw a piece of code where developers, being unaware of such a directive, used custom format string with both datetime.now() and time.time(), a function generator, and on top of it messed with model migrations (it all was about FileField.upload_to if you know what I'm talking about) when they could just use %s. From other undocumented features you might be interested in these: %C  is a century (%Y//100), could be helpful for complimenting %y or something, I guess. %u  is a weekday number with Monday as 1 and Sunday as 7 (as opposed to %w represen...

I usually use Vim for my coding and all other stuff requiring text editing. There are a lot of plugins, scripts, configs, packs for Vim and a lot of them help with Python. But  so far I could not find the pack I'd love and I'm too lazy to make it on my own, so I usually throw out and re-create my whole Vim config dir once a year or so. This time I used Klen's Python Mode  and it's good judging by number of tools involved: almost all code style/syntax helpers I know (pep8, pep257, pyflakes, pylint, mccabe, and pylama to integrate them), autopep8 to help with formatting and stuff, rope for refactoring (sorry, I won't overwhelm this post with links – look for them in readme in github repo). It can more or less integrate with virtualenv and, of course, use Python syntax and identation plugins for Vim. It provides commands for almost everything but doesn't provide a lot of convenient hot-keys. Also there are no hotkeys for Django stuff: I'd like to have hotke...