29 Jul 2016

feedPlanet Twisted

Glyph Lefkowitz: Don’t Trust Sourceforge, Ever

If you use a computer and you use the Internet, chances are you'll eventually find some software that, for whatever reason, is still hosted on Sourceforge. In case you're not familiar with it, Sourceforge is a publicly-available malware vector that also sometimes contains useful open source binary downloads, especially for Windows.

In addition to injecting malware into their downloads (a practice they claim, hopefully truthfully, to have stopped), Sourceforge also presents an initial download page over HTTPS, then redirects the user to HTTP for the download itself, snatching defeat from the jaws of victory. This is fantastically irresponsible, especially for a site offering un-sandboxed binaries for download, especially in the era of Let's Encrypt where getting a TLS certificate takes approximately thirty seconds and exactly zero dollars.

So: if you can possibly find your downloads anywhere else, go there.

But, rarely, you will find yourself at the mercy of whatever responsible stewards1 are still operating Sourceforge if you want to get access to some useful software. As it happens, there is a loophole that will let you authenticate the binaries that you download from them so you won't be left vulnerable to an evil barista: their "file release system", the thing you use to upload your projects, will allow you to download other projects as well.

To use it, first, make yourself a sourceforge account. You may need to create a dummy project as well. Sourceforge maintains an HTTPS-accessible list of key fingerprints for all the SSH servers that they operate, so you can verify the public key below.

Then you'll need to connect to their upload server over SFTP, and go to the path /home/frs/project/<the project's name>/.../ to get the file.

I have written a little Python script2 that automates the translation of a Sourceforge file-browser download URL, one that you can get if you right-click on a download in the "files" section of a project's website, and runs the relevant scp command to retrieve the file for you. This isn't on PyPI or anything, and I'm not putting any effort into polishing it further; the best possible outcome of this blog post is that it immediately stops being necessary.

  1. Are you one of those people? I would prefer to be lauding your legacy of decades of valuable contributions to the open source community instead of ridiculing your dangerous incompetence, but repeated bug reports and support emails have gone unanswered. Please get in touch so we can discuss this.

  2. Code:

    #!/usr/bin/env python2
    import sys
    import os
    sfuri = sys.argv[1]
    # for example,
    # http://sourceforge.net/projects/refind/files/0.9.2/refind-bin-0.9.2.zip/download
    import re
    matched = re.match(
    if not matched:
        sys.stderr.write("Not a SourceForge download link.\n")
    project, path = matched.groups()
    sftppath = "/home/frs/project/{project}/{path}".format(project=project, path=path)
    def knows_about_web_sf_net():
        with open(
                os.path.expanduser("~/.ssh/known_hosts"), "rb"
        ) as read_known_hosts:
            data = read_known_hosts.read().split("\n")
            for line in data:
                if 'web.sourceforge.net' in line.split()[0]:
                    return True
        return False
    sfkey = """
    web.sourceforge.net ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA2uifHZbNexw6cXbyg1JnzDitL5VhYs0E65Hk/tLAPmcmm5GuiGeUoI/B0eUSNFsbqzwgwrttjnzKMKiGLN5CWVmlN1IXGGAfLYsQwK6wAu7kYFzkqP4jcwc5Jr9UPRpJdYIK733tSEmzab4qc5Oq8izKQKIaxXNe7FgmL15HjSpatFt9w/ot/CHS78FUAr3j3RwekHCm/jhPeqhlMAgC+jUgNJbFt3DlhDaRMa0NYamVzmX8D47rtmBbEDU3ld6AezWBPUR5Lh7ODOwlfVI58NAf/aYNlmvl2TZiauBCTa7OPYSyXJnIPbQXg6YQlDknNCr0K769EjeIlAfY87Z4tw==
    if not knows_about_web_sf_net():
        with open(
                os.path.expanduser("~/.ssh/known_hosts"), "ab"
        ) as append_known_hosts:
    cmd = "scp web.sourceforge.net:{sftppath} .".format(sftppath=sftppath)

29 Jul 2016 6:06am GMT

06 Jul 2016

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Twisted Matrix Laboratories: Twisted 16.3 Released

On behalf of Twisted Matrix Laboratories, I am honoured to announce the release of Twisted 16.3.0.

The highlights of this release are:

For more information, check the NEWS file (link provided below).

You can find the downloads on PyPI (or alternatively our website). The NEWS file is also available on GitHub.

Many thanks to everyone who had a part in this release - the supporters of the Twisted Software Foundation, the developers who contributed code as well as documentation, and all the people building great things with Twisted!

Twisted Regards,
Amber Brown (HawkOwl)

06 Jul 2016 12:50pm GMT

26 Jun 2016

feedPlanet Twisted

Itamar Turner-Trauring: Code faster by typing less

Sometimes it's disappointing to see how much code you've written in a given day, so few lines for so much effort. There are big picture techniques you can use to do better, like planning ahead so you write the most useful lines of code. But in the end you still want to be producing as much code as possible given the situation. One great way to do that: type less.

If you're only producing a few lines of code in a day, where did all the rest of your time at the keyboard go? As a programmer you spend a lot of time typing, after all. Here's some of what I spend time on:

If you pay attention you will find you spend a significant amount of time on these sort of activities. And there's a pretty good chance you're also wasting time doing them. Consider the following transcript:

$ git add myfile.py
$ git add anotherfile.py
$ git add --interactive justwantsomeofthisone.py
$ git diff | less
$ git commit -m "I wrote some code, hurrah."
$ git push

You're typing the same thing over and over again! Every time you open a file: lots of typing. Every time you find a class definition manually: more typing.

What do programmers do when they encounter manual, repetitive work? Automate! Pretty much every IDE or text editor for programmers has built-in features or 3rd party packages to automate and reduce the amount of time you waste on these manual tasks. That means Emacs, Vim, Sublime, Eclipse or whatever... as long as it's aimed at programmers, is extendable and has a large user base you're probably going to find everything you need.

As an example, on a day to day basis I use the following Emacs add-ons:

Each of these tools saves just a little bit of time... but I use them over and over again every single day. Small savings add up to big ones.

Here's what you should do: every month or two allocate a few hours to investigating and learning new features or tools for your text editor. Whatever your editor there are tools available, and sometimes even just keyboard shortcuts, that will speed up your development. You want to limit how much time you spend on this because too much time spent will counteract any savings. And you want to do this on an ongoing basis because there's always new tools and shortcuts to discover. Over time you will find yourself spending less time typing useless, repetitive text... and with more time available to write code.

26 Jun 2016 4:00am GMT

15 Jun 2016

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Itamar Turner-Trauring: Writing for software engineers: here's the best book I've found

Where some software engineers can only see the immediate path ahead, more experienced software engineers keep the destination in mind and navigate accordingly. Sometimes the narrow road is the path to righteousness, and sometimes the broad road is the path to wickedness, or at least to broken deadlines and unimplemented requirements. How do you learn to see further, beyond the immediate next steps, beyond the stated requirements? One method you can use is writing.

Writing as thinking can help you find better solutions for easy problems, and solve problems that seem impossible. You write a "design document", where "design" is a verb not a noun, an action not a summary. You write down your assumptions, your requirements, your ideas, the presumed tradeoffs and try to nail down the best solution. Unlike vague ideas in your head, written text can be re-read and sharpened. By putting words to paper you force yourself to clarify your ideas, focus your definitions, make your assumptions more explicit. You can also share written documents with others for feedback and evaluation; since software development is a group effort that often means a group of people will be doing the thinking.

Once you've found a better way forward you need to convince others that your chosen path makes sense. That means an additional kind of writing, writing for persuasion and action: explaining your design, convincing the stakeholders.

How do you learn how to write? If you're just starting your journey as a writer you need to find the right guide; there are many kinds of writing with different goals and different styles. Some books obsess over grammar, others focus on academic writing or popular non-fiction. Writing as a programmer is writing in the context of an organization, writing that needs to propel you forward, not merely educate or entertain. This is where Flower and Ackerman's "Writers at Work" will provide a wise and knowledgeable guide. (There are a dozen other books with the same name; make sure you get the right one!)

Linda Flower is one the originators of the cognitive process theory of writing, and so is well suited to writing a book that covers not just surface style, but the process of adapting writing to one's situation. This book won't teach you how to write luminous prose or craft a brilliant academic argument. The first example scenario the book covers is of someone who has joined the Request For Proposal (RFP) group at a software company. The ten page scenario talks about the RFP process in general, how RFPs are usually constructed within the organization, the team in charge of creating RFPs and their various skills and motivations, the fact RFP's may end up in competitors' hands... What this book will teach you is how do the writing you do in your job: complex, action oriented, utilitarian.

"Writers at Work" focuses on process, context, and writing as a form of organizational action, and helps you understand how to approach your task. It will help you answer these questions and more:

For reasons I don't really understand this practical, immensely useful textbook is out of print, and (for now) you can get copies for cheap. Buy a copy, read it, and start writing!

15 Jun 2016 4:00am GMT

07 Jun 2016

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Moshe Zadka: __name__ == __main__ considered harmful

Every single Python tutorial shows the pattern of

# define functions, classes,
# etc.

if __name__ == '__main__':

This is not a good pattern. If your code is not going to be in a Python module, there is no reason not to unconditionally call 'main()' at the bottom. So this code will only be used in modules - where it leads to unpredictable effects. If this module is imported as 'foo', then the identity of 'foo.something' and '__main__.something' will be different, even though they share code.

This leads to hilarious effects like @cache decorators not doing what they are supposed to, parallel registry lists and all kinds of other issues. Hilarious unless you spend a couple of hours debugging why 'isinstance()' is giving incorrect results.

If you want to write a main module, make sure it cannot be imported. In this case, reversed stupidity is intelligence - just reverse the idiom:

# at the top
if __name__ != '__main__':
    raise ImportError("this module cannot be imported")

This, of course, will mean that this module cannot be unit tested: therefore, any non-trivial code should go in a different module that this one imports. Because of this, it is easy to gravitate towards a package. In that case, put the code above in a module called '__main__.py'. This will lead to the following layout for a simple package:

                 # Empty
                 if __name__ != '__main__':
                     raise ImportError("this module cannot be imported")
                 from PACKAGE_NAME import api
                 # Actual code
                 import unittest
                 # Testing code

And then, when executing:

$ python -m PACKAGE_NAME arg1 arg2 arg3

This will work in any environment where the package is on the sys.path: in particular, in any virtualenv where it was pip-installed. Unless a short command-line is important, it allows skipping over creating a console script in setup.py completely, and letting "python -m" be the official CLI. Since pex supports setting a module as an entry point, if this tool needs to be deployed in other environment, it is easy to package into a tool that will execute the script:

$ pex . --entry-point SOME_PACKAGE --output-file toolname

07 Jun 2016 5:40am GMT

05 Jun 2016

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Jonathan Lange: Evolving toward property-based testing with Hypothesis

Many people are quite comfortable writing ordinary unit tests, but feel a bit confused when they start with property-based testing. This post shows how two ordinary programmers started with normal Python unit tests and nudged them incrementally toward property-based tests, gaining many advantages on the way.


I used to work on a command-line tool with an interface much like git's. It had a repository, and within that repository you could create branches and switch between them. Let's call the tool tlr.

It was supposed to behave something like this:

List branches:

$ tlr branch
* master

Switch to an existing branch:

$ tlr checkout foo
* foo

Create a branch and switch to it:

$ tlr checkout -b new-branch
$ tlr branch
* new-branch

Early on, my colleague and I found a bug: when you created a new branch with checkout -b it wouldn't switch to it. The behavior looked something like this:

$ tlr checkout -b new-branch
$ tlr branch
* master

The previously active branch (in this case, master) stayed active, rather than switching to the newly-created branch (new-branch).

Before we fixed the bug, we decided to write a test. I thought this would be a good chance to start using Hypothesis.

Writing a simple test

My colleague was less familiar with Hypothesis than I was, so we started with a plain old Python unit test:

    def test_checkout_new_branch(self):
        Checking out a new branch results in it being the current active
        tmpdir = FilePath(self.mktemp())
        repo = Repository.initialize(tmpdir.path)
        repo.checkout("new-branch", create=True)
        self.assertEqual("new-branch", repo.get_active_branch())

The first thing to notice here is that the string "new-branch" is not actually relevant to the test. It's just a value we picked to exercise the buggy code. The test should be able to pass with any valid branch name.

Even before we started to use Hypothesis, we made this more explicit by making the branch name a parameter to the test:

    def test_checkout_new_branch(self, branch_name="new-branch"):
        tmpdir = FilePath(self.mktemp())
        repo = Repository.initialize(tmpdir.path)
        repo.checkout(branch_name, create=True)
        self.assertEqual(branch_name, repo.get_active_branch())

(For brevity, I'll elide the docstring from the rest of the code examples)

We never manually provided the branch_name parameter, but this change made it more clear that the test ought to pass regardless of the branch name.

Introducing Hypothesis

Once we had a parameter, the next thing was to use Hypothesis to provide the parameter for us. First, we imported Hypothesis:

    from hypothesis import given
    from hypothesis import strategies as st

And then made the simplest change to our test to actually use it:

    def test_checkout_new_branch(self, branch_name):
        tmpdir = FilePath(self.mktemp())
        repo = Repository.initialize(tmpdir.path)
        repo.checkout(branch_name, create=True)
        self.assertEqual(branch_name, repo.get_active_branch())

Here, rather than providing the branch name as a default argument value, we are telling Hypothesis to come up with a branch name for us using the just("new-branch") strategy. This strategy will always come up with "new-branch", so it's actually no different from what we had before.

What we actually wanted to test is that any valid branch name worked. We didn't yet know how to generate any valid branch name, but using a time-honored tradition we pretended that we did:

    def valid_branch_names():
        """Hypothesis strategy to generate arbitrary valid branch names."""
        # TODO: Improve this strategy.
        return st.just("new-branch")

    def test_checkout_new_branch(self, branch_name):
        tmpdir = FilePath(self.mktemp())
        repo = Repository.initialize(tmpdir.path)
        repo.checkout(branch_name, create=True)
        self.assertEqual(branch_name, repo.get_active_branch())

Even if we had stopped here, this would have been an improvement. Although the Hypothesis version of the test doesn't have any extra power over the vanilla version, it is more explicit about what it's testing, and the valid_branch_names() strategy can be re-used by future tests, giving us a single point for improving the coverage of many tests at once.

Expanding the strategy

It's only when we get Hypothesis to start generating our data for us that we really get to take advantage of its bug finding power.

The first thing my colleague and I tried was:

    def valid_branch_names():
        return st.text()

But that failed pretty hard-core.

Turns out branch names were implemented as symlinks on disk, so valid branch name has to be a valid file name on whatever filesystem the tests are running on. This at least rules out empty names, ".", "..", very long names, names with slashes in them, and probably others (it's actually really complicated).

Hypothesis had made something very clear to us: neither my colleague nor I actually knew what a valid branch name should be. None of our interfaces documented it, we had no validators, no clear ideas for rendering & display, nothing. We had just been assuming that people would pick good, normal, sensible names.

It was as if we had suddenly gained the benefit of extensive real-world end-user testing, just by calling the right function. This was:

  1. Awesome. We've found bugs that our users won't.
  2. Annoying. We really didn't want to fix this bug right now.

In the end, we compromised and implemented a relatively conservative strategy to simulate the good, normal, sensible branch names that we expected:

    from string import ascii_lowercase

    VALID_BRANCH_CHARS = ascii_lowercase + '_-.'

    def valid_branch_names():
        # TODO: Handle unicode / weird branch names by rejecting them early, raising nice errors
        # TODO: How do we handle case-insensitive file systems?
        return st.text(alphabet=VALID_BRANCH_CHARS, min_size=1, max_size=112)

Not ideal, but much more extensive than just hard-coding "new-branch", and much clearer communication of intent.

Adding edge cases

There's one valid branch name that this strategy could generate, but probably won't: master. If we left the test just as it is, then one time in a hojillion the strategy would generate "master" and the test would fail.

Rather than waiting on chance, we encoded this in the valid_branch_names strategy, to make it more likely:

    def valid_branch_names():
        return st.text(
            alphabet=letters, min_size=1, max_size=112).map(lambda t: t.lower()) | st.just("master")

When we ran the tests now, they failed with an exception due to the branch master already existing. To fix this, we used assume:

    from hypothesis import assume

    def test_checkout_new_branch(self, branch_name):
        assume(branch_name != "master")
        tmpdir = FilePath(self.mktemp())
        repo = Repository.initialize(tmpdir.path)
        repo.checkout(branch_name, create=True)
        self.assertEqual(branch_name, repo.get_active_branch())

Why did we add master to the valid branch names if we were just going to exclude it anyway? Because when other tests say "give me a valid branch name", we want them to make the decision about whether master is appropriate or not. Any future test author will be compelled to actually think about whether handling master is a thing that they want to do. That's one of the great benefits of Hypothesis: it's like having a rigorous design critic in your team.

Going forward

We stopped there, but we need not have. Just as the test should have held for any branch, it should also hold for any repository. We were just creating an empty repository because it was convenient for us.

If we were to continue, the test would have looked something like this:

    @given(repo=repositories(), branch_name=valid_branch_names())
    def test_checkout_new_branch(self, repo, branch_name):
        Checking out a new branch results in it being the current active
        assume(branch_name not in repo.get_branches())
        repo.checkout(branch_name, create=True)
        self.assertEqual(branch_name, repo.get_active_branch())

This is about as close to a bona fide "property" as you're likely to get in code that isn't a straight-up computer science problem: if you create and switch to a branch that doesn't already exist, the new active branch is the newly created branch.

We got there not by sitting down and thinking about the properties of our software in the abstract, nor by necessarily knowing much about property-based testing, but rather by incrementally taking advantage of features of Python and Hypothesis. On the way, we discovered and, umm, contained a whole class of bugs, and we made sure that all future tests would be heaps more powerful. Win.

This post was originally published on hypothesis.works. I highly recommend checking out their site if you want to test faster and fix more.

05 Jun 2016 3:00pm GMT

31 May 2016

feedPlanet Twisted

Moshe Zadka: Stop Feeling Guilty about Writing Classes

I've seen a few talks about "stop writing classes". I think they have a point, but it is a little over-stated. All debates are bravery debates, so it is hard to say which problem is harder - but as a recovering class-writing-guiltoholic, let me admit this: I took this too far. I was avoiding classes when I shouldn't have.

Classes are best kept small

It is true that classes are best kept small. Any "method" which is not really designed to be overridden is often best implemented as a function that accepts a "duck-type" (or a more formal interface).

This, of course, sometimes leads to…

If a class has only one public method, except __init__, it wants to be a function

Especially given function.partial, it is not needed to decide ahead of time which arguments are "static" and which are "dynamic"

Classes are useful as data packets

This is the usual counter-point to the first two anti-class sentiments: a class which is nothing more than a bunch of attributes (a good example is the TCP envelope: source IP/target IP/source port/target port) are useful. Sure, they could be passed around as dictionaries, but this does not make things better. Just use attrs - and it is often useful to write two more methods:

It is perfectly ok to write this class rather than shipping dictionaries around. If nothing else, error messages will be a lot nicer. Please do not feel guilty.

31 May 2016 2:43pm GMT

19 May 2016

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Hynek Schlawack: Conditional Python Dependencies

Since the inception of wheels that install Python packages without executing arbitrary code, we need a static way to encode conditional dependencies for our packages. Thanks to PEP 508 we do have a blessed way but sadly the prevalence of old setuptools versions makes it a minefield to use.

19 May 2016 12:00am GMT

18 May 2016

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Twisted Matrix Laboratories: Twisted 16.2 Released

On behalf of Twisted Matrix Laboratories, I am honoured to announce the release of Twisted 16.2!

Just in time for PyCon US, this release brings a few headlining features (like the haproxy endpoint) and the continuation of the modernisation of the codebase. More Python 3, less deprecated code, what's not to like?

For more information, check the NEWS file (link provided below).

You can find the downloads on PyPI (or alternatively our website). The NEWS file is also available on GitHub.

Many thanks to everyone who had a part in this release - the supporters of the Twisted Software Foundation, the developers who contributed code as well as documentation, and all the people building great things with Twisted!

Twisted Regards,
Amber Brown (HawkOwl)

18 May 2016 5:10pm GMT

06 May 2016

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Moshe Zadka: Forking Skip-level Dependencies

I have recently found I explain this concept over and over to people, so I want to have a reference.

Most modern languages comes with a "dependency manager" of sorts that helps manage the 3rd party libraries a given project uses. Rust has Cargo, Node.js has npm, Python has pip and so on. All of these do some things well and some things poorly. But one thing that can be done (well or poorly) is "support forking skip-level dependencies".

In order to explain what I mean, here as an example: our project is PlanetLocator, a program to tell the user which direction they should face to see a planet. It depends on a library called Astronomy. Astronomy depends on Physics. Physics depends on Math.

PlanetLocator is a SaaS, running on our servers. One day, we find Math has a critical bug, leading to a remote execution vulnerability. This is pretty bad, because it can be triggered via our application by simply asking PlanetLocator for the location of Mars at a specific date in the future. Luckily, the bug is simple - in Math's definition of Pi, we need to add a couple of significant digits.

How easy is it to fix?

Well, assume PlanetLocator is written in Go, and not using any package manager. A typical import statement in PlanetLocator is

import "github.com/astronomy/astronomy"

A typical import statement in Astronomy is

import "github.com/physics/physics

..and so on.

We fork Math over to "github.com/planetlocator/math" and fix the vulnerability. Now we have to fork over physics to use the forked math, and astronomy to use the forked physics and finally, change all of our imports to import the forked astronomy - and Physics, Astronomy and PlanetLocator had no bugs!

Now assume, instead, we had used Python. In our requirements.txt file, we could put


and voila! even though Physics' "setup.py" said "install_requires=['math']", it will get our forked math.

When starting to use a new language/dependency manager, the first question to ask is: will it support me forking skip-level dependencies? Because every upstream maintainer is, effectively, an absent-maintainer if rapid response is at stake (for any reason - I chose security above, but it might be beating the competition to a deadline, or fulfilling contractual obligations).

06 May 2016 4:17am GMT

03 May 2016

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Glyph Lefkowitz: Letters To The Editor: Re: Email

Since I removed comments from this blog, I've been asking y'all to email me when you have feedback, with the promise that I'd publish the good bits. Today I'm making good on that for the first time, with this lovely missive from Adam Doherty:

I just wanted to say thank you. As someone who is never able to say no, your article on email struck a chord with me. I have had Gmail since the beginning, since the days of hoping for an invitation. And the day I received my invitation was the the last day my inbox was ever empty.

Prior to reading your article I had over 40,000 unread messages. It used to be a sort of running joke; I never delete anything. Realistically though was I ever going to do anything with them?

With 40,000 unread messages in your inbox, you start to miss messages that are actually important. Messages that must become tasks, tasks that must be completed.

Last night I took your advice; and that is saying something - most of the things I read via HN are just noise. This however spoke to me directly.

I archived everything older than two weeks, was down to 477 messages and kept pruning. So much of the email we get on a daily basis is also noise. Those messages took me half a second to hit archive and move on.

I went to bed with zero messages in my inbox, woke up with 21, archived 19, actioned 2 and then archived those.

Seriously, thank you so very much. I am unburdened.

First, I'd like to thank Adam for writing in. I really do appreciate the feedback.

Second, I wanted to post this here not in service of showcasing my awesomeness1, but rather to demonstrate that getting to the bottom of your email can have a profound effect on your state of mind. Even if it's a running joke, even if you don't think it's stressing you out, there's a good chance that, somewhere in the back of your mind, it is. After all, if you really don't care, what's stopping you from hitting select all / archive right now?

At the very least, if you did that, your mail app would load faster.

  1. although, let there be no doubt, I am awesome

03 May 2016 6:06am GMT

27 Apr 2016

feedPlanet Twisted

Itamar Turner-Trauring: How you should choose which technology to learn next

Keeping up with the growing software ecosystem - new databases, new programming languages, new web frameworks - becomes harder and harder every year as more and more software is written. It is impossible to learn all existing technologies, let alone the new ones being released every day. If you want to learn another programming language you can choose from Dart, Swift, Go, Idris, Futhark, Ceylon, Zimbu, Elm, Elixir, Vala, OCaml, LiveScript, Oz, R, TypeScript, PureScript, Haskell, F#, Scala, Dylan, Squeak, Julia, CoffeeScript... and about a thousand more, if you're still awake. This stream of new technologies can be overwhelming, a constant worry that your skills are getting rusty and out of date.

Luckily you don't need to learn all technologies, and you are likely to use only a small subset during your tenure as a programmer. Instead your goal should be to maximize your return on investment: learn the most useful tools, with the least amount of effort. How then should you choose which technologies to learn?

Don't spend too much time on technologies which are either too close or too far from your current set of knowledge. If you are an expert on PostgreSQL then learning another relational database like MySQL won't teach you much. Your existing knowledge is transferable for the most part, and you'd have no trouble applying for a job requiring MySQL knowledge. On the other hand a technology that is too far from your current tools will be much more difficult to learn, e.g. switching from web development to real-time embedded devices.

Focus on technologies that can build on your existing knowledge while still being different enough to teach you something new. Learning these technologies provides multiple benefits:

There are three ways you can build on your existing knowledge of tools and technologies:

  1. Branch out to nearby technologies: If you're a backend web developer you are interacting with a database, with networking via the HTTP protocol, with a browser running Javascript. You will end up knowing at least a little bit about these technologies, and you have some sense of how they interact with the technology you already know well. These are all great candidates for a new technology to learn next.
  2. Alternative solutions for a problem you understand: If you are an expert on the PostgreSQL database you might want to learn MongoDB. It's still a database, solving a problem whose parameters you already understand: how to store and search structured data. But the way MongoDB solves this problem is fundamentally different than PostgreSQL, which means you will learn a lot.
  3. Enhance your usage of existing tools: Tools for testing your existing technology stack can make you a better programmer by providing faster feedback and a broader view of software quality and defects. Learning how to better use a sophisticated text editor like Emacs/Vim or an IDE like Eclipse with your programming language of choice can make you a more productive programmer.

Neither you nor any other programmer will ever be able to learn all the technologies in use today: there are just too many. What you can and should do is learn those that will help with your current projects, and those that you can learn more easily. The more technologies you know, the broader the range of technologies you have at least partial access to, and the easier it will be to learn new ones.

27 Apr 2016 4:00am GMT

24 Apr 2016

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Glyph Lefkowitz: Email Isn’t The Thing You’re Bad At

I've been using the Internet for a good 25 years now, and I've been lucky enough to have some perspective dating back farther than that. The common refrain for my entire tenure here:

We all get too much email.

A New, New, New, New Hope

Luckily, something is always on the cusp of replacing email. AOL instant messenger will totally replace it. Then it was blogging. RSS. MySpace. Then it was FriendFeed. Then Twitter. Then Facebook.

Today, it's in vogue to talk about how Slack is going to replace email. As someone who has seen this play out a dozen times now, let me give you a little spoiler:

Slack is not going to replace email.

But Slack isn't the problem here, either. It's just another communication tool.

The problem of email overload is both ancient and persistent. If the problem were really with "email", then, presumably, one of the nine million email apps that dot the app-stores like mushrooms sprouting from a globe-spanning mycelium would have just solved it by now, and we could all move on with our lives. Instead, it is permanently in vogue1 to talk about how overloaded we all are.

If not email, then what?

If you have twenty-four thousand unread emails in your Inbox, like some kind of goddamn animal, what you're bad at is not email, it's transactional interactions.

Different communication media have different characteristics, but the defining characteristic of email is that it is the primary mode of communication that we use, both professionally and personally, when we are asking someone else to perform a task.

Of course you might use any form of communication to communicate tasks to another person. But other forms - especially the currently popular real-time methods - appear as a bi-directional communication, and are largely immutable. Email's distinguishing characteristic is that it is discrete; each message is its own entity with its own ID. Emails may also be annotated, whether with flags, replied-to markers, labels, placement in folders, archiving, or deleting. Contrast this with a group chat in IRC, iMessage, or Slack, where the log is mostly2 unchangeable, and the only available annotation is "did your scrollbar ever move down past this point"; each individual message has only one bit of associated information. Unless you have catlike reflexes and an unbelievably obsessive-compulsive personality, it is highly unlikely that you will carefully set the "read" flag on each and every message in an extended conversation.

All this makes email much more suitable for communicating a task, because the recipient can file it according to their system for tracking tasks, come back to it later, and generally treat the message itself as an artifact. By contrast if I were to just walk up to you on the street and say "hey can you do this for me", you will almost certainly just forget.

The word "task" might seem heavy-weight for some of the things that email is used for, but tasks come in all sizes. One task might be "click this link to confirm your sign-up on this website". Another might be "choose a time to get together for coffee". Or "please pass along my resume to your hiring department". Yet another might be "send me the final draft of the Henderson report".

Email is also used for conveying information: here are the minutes from that meeting we were just in. Here is transcription of the whiteboard from that design session. Here are some photos from our family vacation. But even in these cases, a task is implied: read these minutes and see if they're accurate; inspect this diagram and use it to inform your design; look at these photos and just enjoy them.

So here's the thing that you're bad at, which is why none of the fifty different email apps you've bought for your phone have fixed the problem: when you get these messages, you aren't making a conscious decision about:

  1. how important the message is to you
  2. whether you want to act on them at all
  3. when you want to act on them
  4. what exact action you want to take
  5. what the consequences of taking or not taking that action will be

This means that when someone asks you to do a thing, you probably aren't going to do it. You're going to pretend to commit to it, and then you're going to flake out when push comes to shove. You're going to keep context-switching until all the deadlines have passed.

In other words:

The thing you are bad at is saying 'no' to people.

Sometimes it's not obvious that what you're doing is saying 'no'. For many of us - and I certainly fall into this category - a lot of the messages we get are vaguely informational. They're from random project mailing lists, perhaps they're discussions between other people, and it's unclear what we should do about them (or if we should do anything at all). We hang on to them (piling up in our Inboxes) because they might be relevant in the future. I am not advocating that you have to reply to every dumb mailing list email with a 5-part action plan and a Scrum meeting invite: that would be a disaster. You don't have time for that. You really shouldn't have time for that.

The trick about getting to Inbox Zero3 is not in somehow becoming an email-reading machine, but in realizing that most email is worthless, and that's OK. If you're not going to do anything with it, just archive it and forget about it. If you're subscribed to a mailing list where only 1 out of 1000 messages actually represents something you should do about it, archive all the rest after only answering the question "is this the one I should do something about?". You can answer that question after just glancing at the subject; there are times when checking my email I will be hitting "archive" with a 1-second frequency. If you are on a list where zero messages are ever interesting enough to read in their entirety or do anything about, then of course you should unsubscribe.

Once you've dug yourself into a hole with thousands of "I don't know what I should do with this" messages, it's time to declare email bankruptcy. If you have 24,000 messages in your Inbox, let me be real with you: you are never, ever going to answer all those messages. You do not need a smartwatch to tell you exactly how many messages you are never going to reply to.

We're In This Together, Me Especially

A lot of guidance about what to do with your email addresses email overload as a personal problem. Over the years of developing my tips and tricks for dealing with it, I certainly saw it that way. But lately, I'm starting to see that it has pernicious social effects.

If you have 24,000 messages in your Inbox, that means you aren't keeping track or setting priorities on which tasks you want to complete. But just because you're not setting those priorities, that doesn't mean nobody is. It means you are letting availability heuristic - whatever is "latest and loudest" - govern access to your attention, and therefore your time. By doing this, you are rewarding people (or #brands) who contact you repeatedly, over inappropriate channels, and generally try to flood your attention with their priorities instead of your own. This, in turn, creates a culture where it is considered reasonable and appropriate to assume that you need to do that in order to get someone's attention.

Since we live in the era of subtext and implication, I should explicitly say that I'm not describing any specific work environment or community. I used to have an email startup, and so I thought about this stuff very heavily for almost a decade. I have seen email habits at dozens of companies, and I help people in the open source community with their email on a regular basis. So I'm not throwing shade: almost everybody is terrible at this.

And that is the one way that email, in the sense of the tools and programs we use to process it, is at fault: technology has made it easier and easier to ask people to do more and more things, without giving us better tools or training to deal with the increasingly huge array of demands on our time. It's easier than ever to say "hey could you do this for me" and harder than ever to just say "no, too busy".

Mostly, though, I want you to know that this isn't just about you any more. It's about someone much more important than you: me. I'm tired of sending reply after reply to people asking to "just circle back" or asking if I've seen their email. Yes, I've seen your email. I have a long backlog of tasks, and, like anyone, I have trouble managing them and getting them all done4, and I frequently have to decide that certain things are just not important enough to do. Sometimes it takes me a couple of weeks to get to a message. Sometimes I never do. But, it's impossible to be mad at somebody for "just checking in" for the fourth time when this is probably the only possible way they ever manage to get anyone else to do anything.

I don't want to end on a downer here, though. And I don't have a book to sell you which will solve all your productivity problems. I know that if I lay out some incredibly elaborate system all at once, it'll seem overwhelming. I know that if I point you at some amazing gadget that helps you keep track of what you want to do, you'll either balk at the price or get lost fiddling with all its knobs and buttons and not getting a lot of benefit out of it. So if I'm describing a problem that you have here, here's what I want you to do.

Step zero is setting aside some time. This will probably take you a few hours, but trust me; they will be well-spent.

Email Bankruptcy

First, you need to declare email bankruptcy. Select every message in your Inbox older than 2 weeks. Archive them all, right now. In the past, you might have to worry about deleting those messages, but modern email systems pretty much universally have more storage than you'll ever need. So rest assured that if you actually need to do anything with these messages, they'll all be in your archive. But anything in your Inbox right now older than a couple of weeks is just never going to get dealt with, and it's time to accept that fact. Again, this part of the process is not about making a decision yet, it's just about accepting a reality.

Mailbox Three

One extra tweak I would suggest here is to get rid of all of your email folders and filters. It seems like many folks with big email problems have tried to address this by ever-finer-grained classification of messages, ever more byzantine email rules. At least, it's common for me, when looking over someone's shoulder to see 24,000 messages, it's common to also see 50 folders. Probably these aren't helping you very much.

In older email systems, it was necessary to construct elaborate header-based filtering systems so that you can later identify those messages in certain specific ways, like "message X went to this mailing list". However, this was an incomplete hack, a workaround for a missing feature. Almost all modern email clients (and if yours doesn't do this, switch) allow you to locate messages like this via search.

Your mail system ought to have 3 folders:

  1. Inbox, which you process to discover tasks,
  2. Drafts, which you use to save progress on replies, and
  3. Archive, the folder which you access only by searching for information you need when performing a task.

Getting rid of unnecessary folders and queries and filter rules will remove things that you can fiddle with.

Moving individual units of trash between different heaps of trash is not being productive, and by removing all the different folders you can shuffle your messages into before actually acting upon them you will make better use of your time spent looking at your email client.

There's one exception to this rule, which is filters that do nothing but cause a message to skip your Inbox and go straight to the archive. The reason that this type of filter is different is that there are certain sources or patterns of message which are not actionable, but rather, a useful source of reference material that is only available as a stream of emails. Messages like that should, indeed, not show up in your Inbox. But, there's no reason to file them into a specific folder or set of folders; you can always find them with a search.

Make A Place For Tasks

Next, you need to get a task list. Your email is not a task list; tasks are things that you decided you're going to do, not things that other people have asked you to do5. Critically, you are going to need to parse e-mails into tasks. To explain why, let's have a little arithmetic aside.

Let's say it only takes you 45 seconds to go from reading a message to deciding what it really means you should do; so, it only takes 20 seconds to go from looking at the message to remembering what you need to do about it. This means that by the time you get to 180 un-processed messages that you need to do something about in your Inbox, you'll be spending an hour a day doing nothing but remembering what those messages mean, before you do anything related to actually living your life, even including checking for new messages.

What should you use for the task list? On some level, this doesn't really matter. It only needs one really important property: you need to trust that if you put something onto it, you'll see it at the appropriate time. How exactly that works depends heavily on your own personal relationship with your computers and devices; it might just be a physical piece of paper. But for most of us living in a multi-device world, something that synchronizes to some kind of cloud service is important, so Wunderlist or Remember the Milk are good places to start, with free accounts.

Turn Messages Into Tasks

The next step - and this is really the first day of the rest of your life - start at the oldest message in your Inbox, and work forward in time. Look at only one message at a time. Decide whether this message is a meaningful task that you should accomplish.

If you decide a message represents a task, then make a new task on your task list. Decide what the task actually is, and describe it in words; don't create tasks like "answer this message". Why do you need to answer it? Do you need to gather any information first?

If you need to access information from the message in order to accomplish the task, then be sure to note in your task how to get back to the email. Depending on what your mail client is, it may be easier or harder to do this6, but in the worst case, following the guidelines above about eliminating unnecessary folders and filing in your email client, just put a hint into your task list about how to search for the message in question unambiguously.

Once you've done that:

Archive the message immediately.

The record that you need to do something about the message now lives in your task list, not your email client. You've processed it, and so it should no longer remain in your inbox.

If you decide a message doesn't represent a task, then:

Archive the message immediately.

Do not move on to the next message until you have archived this message. Do not look ahead7. The presence of a message in your Inbox means you need to make a decision about it. Follow the touch-move rule with your email. If you skip over messages habitually and decide you'll "just get back to it in a minute", that minute will turn into 4 months and you'll be right back where you were before.

Circling back to the subject of this post; once again, this isn't really specific to email. You should follow roughly the same workflow when someone asks you to do a task in a meeting, or in Slack, or on your Discourse board, or wherever, if you think that the task is actually important enough to do. Note the slack timestamp and a snippet of the message so you can search for it again, if there is a relevant attachment. The thing that makes email different is really just the presence of an email box.

Banish The Blue Dot

Almost all email clients have a way of tracking "unread" messages; they cheerfully display counters of them. Ignore this information; it is useless. Messages have two states: in your inbox (unprocessed) and in your archive (processed). "Read" vs. "Unread" can be, at best, of minimal utility when resuming an interrupted scanning session. But, you are always only ever looking at the oldest message first, right? So none of the messages below it should be unread anyway...

Be Ruthless

As you try to start translating your flood of inbound communications into an actionable set of tasks you can actually accomplish, you are going to notice that your task list is going to grow and grow just as your Inbox was before. This is the hardest step:

Decide you are not going to do those tasks, and simply delete them. Sometimes, a task's entire life-cycle is to be created from an email, exist for ten minutes, and then have you come back to look at it and then delete it. This might feel pointless, but in going through that process, you are learning something extremely valuable: you are learning what sorts of things are not actually important enough to do you do.

If every single message you get from some automated system provokes this kind of reaction, that will give you a clue that said system is wasting your time, and just making you feel anxious about work you're never really going to get to, which can then lead to you un-subscribing or filtering messages from that system.

Tasks Before Messages

To thine own self, not thy Inbox, be true.

Try to start your day by looking at the things you've consciously decided to do. Don't look at your email, don't look at Slack; look at your calendar, and look at your task list.

One of those tasks, probably, is a daily reminder to "check your email", but that reminder is there more to remind you to only do it once than to prevent you from forgetting.

I say "try" because this part is always going to be a challenge; while I mentioned earlier that you don't want to unthinkingly give in to availability heuristic, you also have to acknowledge that the reason it's called a "cognitive bias" is because it's part of human cognition. There will always be a constant anxious temptation to just check for new stuff; for those of us who have a predisposition towards excessive scanning behavior have it more than others.

Why Email?

We all need to make commitments in our daily lives. We need to do things for other people. And when we make a commitment, we want to be telling the truth. I want you to try to do all these things so you can be better at that. It's impossible to truthfully make a commitment to spend some time to perform some task in the future if, realistically, you know that all your time in the future will be consumed by whatever the top 3 highest-priority angry voicemails you have on that day are.

Email is a challenging social problem, but I am tired of email, especially the user interface of email applications, getting the blame for what is, at its heart, a problem of interpersonal relations. It's like noticing that you get a lot of bills through the mail, and then blaming the state of your finances on the colors of the paint in your apartment building's mail room. Of course, the UI of an email app can encourage good or bad habits, but Gmail gave us a prominent "Archive" button a decade ago, and we still have all the same terrible habits that were plaguing Outlook users in the 90s.

Of course, there's a lot more to "productivity" than just making a list of the things you're going to do. Some tools can really help you manage that list a lot better. But all they can help you to do is to stop working on the wrong things, and start working on the right ones. Actually being more productive, in the sense of getting more units of work out of a day, is something you get from keeping yourself healthy, happy, and well-rested, not from an email filing system.

You can't violate causality to put more hours into the day, and as a frail and finite human being, there's only so much work you can reasonably squeeze in before you die.

The reason I care a lot about salvaging email specifically is that it remains the best medium for communication that allows you to be in control of your own time, and by extension, the best medium for allowing people to do creative work.

Asking someone to do something via SMS doesn't scale; if you have hundreds of unread texts there's no way to put them in order, no way to classify them as "finished" and "not finished", so you need to keep it to the number of things you can fit in short term memory. Not to mention the fact that text messaging is almost by definition an interruption - by default, it causes a device in someone's pocket to buzz. Asking someone to do something in group chat, such as IRC or Slack, is similarly time-dependent; if they are around, it becomes an interruption, and if they're not around, you have to keep asking and asking over and over again, which makes it really inefficient for the asker (or the asker can use a @highlight, and assume that Slack will send the recipient, guess what, an email).

Social media often comes up as another possible replacement for email, but its sort order is even worse than "only the most recent and most frequently repeated". Messages are instead sorted by value to advertisers or likeliness to increase 'engagement'", i.e. most likely to keep you looking at this social media site rather than doing any real work.

For those of us who require long stretches of uninterrupted time to produce something good - "creatives", or whatever today's awkward buzzword for intersection of writers, programmers, graphic designers, illustrators, and so on, is - we need an inbound task queue that we can have some level of control over. Something that we can check at a time of our choosing, something that we can apply filtering to in order to protect access to our attention, something that maintains the chain of request/reply for reference when we have to pick up a thread we've had to let go of for a while. Some way to be in touch with our customers, our users, and our fans, without being constantly interrupted. Because if we don't give those who need to communicate with such a tool, they'll just blast @everyone messages into our slack channels and @mentions onto Twitter and texting us Hey, got a minute? until we have to quit everything to try and get some work done.

Questions about this post?

Go ahead and send me an email.


As always, any errors or bad ideas are certainly my own.

First of all, Merlin Mann, whose writing and podcasting were the inspiration, direct or indirect, for many of my thoughts on this subject; and who sets a good example because he won't answer your email.

Thanks also to David Reid for introducing me to Merlin's work, as well as Alex Gaynor, Tristan Seligmann, Donald Stufft, Cory Benfield, Piët Delport, Amber Brown, and Ashwini Oruganti for feedback on drafts.

  1. Email is so culturally pervasive that it is literally in Vogue, although in fairness this is not a reference to the overflowing-Inbox problem that I'm discussing here.

  2. I find the "edit" function in Slack maddening; although I appreciate why it was added, it's easy to retroactively completely change the meaning of an entire conversation in ways that make it very confusing for those reading later. You don't even have to do this intentionally; sometimes you make a legitimate mistake, like forgetting the word "not", and the next 5 or 6 messages are about resolving that confusion; then, you go back and edit, and it looks like your colleagues correcting you are a pedantic version of Mr. Magoo, unable to see that you were correct the first time.

  3. There, I said it. Are you happy now?

  4. Just to clarify: nothing in this post should be construed as me berating you for not getting more work done, or for ever failing to meet any commitment no matter how casual. Quite the opposite: what I'm saying you need to do is acknowledge that you're going to screw up and rather than hold a thousand emails in your inbox in the vain hope that you won't, just send a quick apology and move on.

  5. Maybe you decided to do the thing because your boss asked you to do it and failing to do it would cost you your job, but nevertheless, that is a conscious decision that you are making; not everybody gets to have "boss" priority, and unless your job is a true Orwellian nightmare, not everything your boss says in email is an instant career-ending catastrophe.

  6. In Gmail, you can usually just copy a link to the message itself. If you're using OS X's Mail.app, you can use this Python script to generate links that, when clicked, will open the Mail app:

    from __future__ import (print_function, unicode_literals,
                            absolute_import, division)
    from ScriptingBridge import SBApplication
    import urllib
    mail = SBApplication.applicationWithBundleIdentifier_("com.apple.mail")
    for viewer in mail.messageViewers():
        for message in viewer.selectedMessages():
            for header in message.headers():
                name = header.name()
                if name.lower() == "message-id":
                    content = header.content()
                    print("message:" + urllib.quote(content))

    You can then paste these links into just about any task tracker; if they don't become clickable, you can paste them into Safari's URL bar or pass them to the open command-line tool.

  7. The one exception here is that you can look ahead in the same thread to see if someone has already replied.

24 Apr 2016 11:54pm GMT

Moshe Zadka: Use virtualenv

In a conversation recently with a friend, we agreed that "something the instructions tell you to do 'sudo pip install'…which is good, because then you know to ignore them".

There is never a need for "sudo pip install", and doing it is an anti-pattern. Instead, all installation of packages should go into a virtualenv. The only exception is, of course, virtualenv (and arguably, pip and wheel). I got enough questions about this that I wanted to write up an explanation about the how, why and why the counter-arguments are wrong.

What is virtualenv?

The documentation says:

virtualenv is a tool to create isolated Python environments.

The basic problem being addressed is one of dependencies and versions, and indirectly permissions. Imagine you have an application that needs version 1 of LibFoo, but another application requires version 2. How can you use both these applications? If you install everything into/usr/lib/python2.7/site-packages (or whatever your platform's standard location is), it's easy to end up in a situation where you unintentionally upgrade an application that shouldn't be upgraded.

Or more generally, what if you want to install an application and leave it be? If an application works, any change in its libraries or the versions of those libraries can break the application.

The tl:dr; is:

The first problem is the one the "sudo" comment addresses - but the real issues stem from the second and third: not using a virtual environment leads to the potential of conflicts and dependency hell.

How to use virtualenv?

Creating a virtual environment is easy:

$ virtualenv dirname

will create the directory, if it does not exist, and then create a virtual environment in it. It is possible to use it either activated or unactivated. Activating a virtual environment is done by

$ . dirname/bin/activate

this will make python, as well as any script installed using setuptools' "console_scripts" option in the virtual environment, on the command-execution path. The most important of those is pip, and so using pip will install into the virtual environment.

It is also possible to use a virtual environment without activating it, by directly calling dirname/bin/python or any other console script. Again, pip is an example of those, and used for installing into the virtual environment.

Installing tools for "general use"

I have seen a couple of times the argument that when installing tools for general use it makes sense to install them into the system install. I do not think that this is a reasonable exception for two reasons:

There are a few good alternatives for this:

Exploratory programming

People often use Python for exploratory programming. That's great! Note that since pip 7, pip is building and caching wheels by default. This means that creating virtual environments is even cheaper: tearing down an environment and building a new one will not require recompilation. Because of that, it is easy to treat virtual environments as disposable except for configuration: activate a virtual environment, explore - and whenever needing to move things into production, 'pip freeze' will allow easy recreation of the environment.

24 Apr 2016 4:54am GMT

20 Apr 2016

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Glyph Lefkowitz: Far too many things can stop the BLOB

It occurs to me that the lack of a standard, well-supported, memory-efficient interface for BLOBs in multiple programming languages is one of the primary driving factors of poor scalability characteristics of open source SaaS applications.

Applications like Gitlab, Redmine, Trac, Wordpress, and so on, all need to store potentially large files ("attachments"). Frequently, they elect to store these attachments (at least by default) in a dedicated filesystem directory. This leads to a number of tricky concurrency issues, as the filesystem has different (and divorced) concurrency semantics from the backend database, and resides only on the individual API nodes, rather than in the shared namespace of the attached database.

Some databases do support writing to BLOBs like files. Postgres, SQLite, and Oracle do, although it seems MySQL lags behind in this area (although I'd love to be corrected on this front). But many higher-level API bindings for these databases don't expose support for BLOBs in an efficient way.

Directly using the filesystem, as opposed to a backing service, breaks the "expected" scaling behavior of the front-end portion of a web application. Using an object store, like Cloud Files or S3, is a good option to achieve high scalability for public-facing applications, but that creates additional deployment complexity.

So, as both a plea to others and a note to myself: if you're writing a database-backed application that needs to store some data, please consider making "store it in the database as BLOBs" an option. And if your particular database client library doesn't support it, consider filing a bug.

20 Apr 2016 1:01am GMT

15 Apr 2016

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Itamar Turner-Trauring: Improving your skills as a 9 to 5 programmer

Do you only code 9 to 5, but wonder if that's good enough? Do you see other programmers working on personal projects or open source projects, going to hackathons, and spending all their spare time writing software? You might think that as someone who only writes software at their job, who only works 9-5, you will never be as good. You might believe that only someone who eats, sleeps and breathes code can excel. But actually it's possible to stick to a 40-hour week and still be a valuable, skilled programmer.

Working on personal or open source software projects doesn't automatically make you better programmer. Hackathons might even be a net negative if they give you the impression that building software to arbitrary deadlines while exhausted is a reasonable way to produce anything of value. There are inherent limits to your productive working hours. If you don't feel like spending more time coding when you get home, then don't: you'll be too tired or unfocused to gain anything.

Spending time on side projects does have some value, but the most useful result is not so much practice as knowledge. Established software projects tend to use older technology and techniques, simply because they've been in existence for a while. The main value you get from working on other software projects and interacting with developers outside of work is knowledge of:

  1. A broader range of technologies and tools.
  2. New techniques and processes. Perhaps your company doesn't do much testing, but you can learn about test-driven development elsewhere.

Having a broad range of tools and techniques to reach for is a valuable skill both at your job and when looking for a new job. But actual coding is not an efficient way to gain this knowledge. You don't actually need to use new tools and techniques, and you'll never really have to time to learn all tools and all techniques in detail anyway. You get the most value just from having some sense of what tools and techniques are out there, what they do and when they're useful. If a new tool you discover is immediately relevant to your job you can just learn it during working hours, and if it's not you can should just file it away in your brain for later.

Learning about new tools can also help you find a new job, even when you don't actually use them. I was once asked at an interview about the difference between NoSQL and traditional databases. At the time I'd never used MongoDB or any other NoSQL database, but I knew enough to answer satisfactorily. Being able to answer that question told the interviewer I'd be able to use that tool, if necessary, even if I hadn't done it before.

Instead of coding in your spare time you can get similar benefits, and more efficiently, by directly focusing on acquiring knowledge of new tools and techniques. And since this knowledge will benefit your employer and you don't need to spend significant time on it, you can acquire it during working hours. You're never actually working every single minute of your day, you always have some time when you're slacking off on the Internet. Perhaps you're doing so right now! You can use that time to expand your knowledge.

Each week you should allocate one hour of your time at work to learning about new tools and techniques. Choosing a particular time will help you do this on a regular basis. Personally I'd choose Friday afternoons, since by that point in the week I'm not achieving much anyway. Don't skip this hour just because of deadlines or tiredness. You'll do better at deadlines, and be less tired, if you know of the right tools and techniques to efficiently solve the problems you encounter at your job.

15 Apr 2016 4:00am GMT