Welcome ! This is the personal site / blog of Graham King. Most people come for the credit card generator, but I think the Categories (top right) are more interesting.
There are lots of easy ways to improve the output of your command line scripts, without going full curses, such as single-line output, using bold text and colors, and even measuring the screen width and height.
The examples are in Python, with a summary example in Go (golang) at the end.
Single line with \r (carriage return)
Instead of printing a \n (which most ‘print’ methods do by default), print a \r. That sends the cursor back to the beginning of the current line (carriage return), without dropping down to a new line (line feed).
import time, sys
total = 10
for i in range(total):
sys.stdout.write('%d / %d\r' % (i, total))
sys.stdout.flush()
time.sleep(0.5)
print('Done ')
And this is the essential broader point–as a programmer you must have a series of wins, every single day. It is the Deus Ex Machina of hacker success. It is what makes you eager for the next feature, and the next after that. And a large team is poison to small wins. The nature of large teams is such that even when you do have wins, they come after long, tiresome and disproportionately many hurdles. And this takes all the wind out of them.
For me, that’s really the crux of it. As a programmer, it kills you to not get stuff done. Large teams necessarily involve more communication, more complexity, and less getting stuff done. Large teams are a programmers equivalent of retirement.
In every city there are two different humours, one rising from the people’s desire not to be ordered and commanded by the nobles, and the other from the desire of the nobles to command and oppress the people.
You cannot satisfy the nobles honestly and without harming others, but you certainly can satisfy the people. In fact, the aim of the common people is more honest that that of the nobles, since the nobles want to oppress others, while the people simply want not to be oppressed.
The Prince must always live among the same people, but he can do very well without a particular set of noblemen.
Substitute nobles with the 1%, and substitute Prince with President, and you get the advice he would probably give today.
Monitoring iPad network traffic, and blocking advert download.
An article on monitoring iPhone traffic by Craig Dunn got me wondering what the iPad is sending over the wire. That led me to blocking many of the adverts apps show. Here’s how.
1. Setup a proxy (squid on ubuntu)
First you need to setup a proxy, and send all your iPad’s network traffic through that. On Ubuntu squid is easy to setup: sudo apt-get install squid
After a frustrating time trying to find a memory leak in my Python code with guppy / heappy hpy, I tried objgraph and, wow, it makes it so easy! Here’s what you do:
pip install objgraph
At the relevant point in your code, add an import pdb; pdb.set_trace() to drop into the debugger. Then just follow the docs on finding memory leaks with objgraph. In short you do:
Ignore that output. Call the function that leaks memory, iterate once through you loop, whatever you need to do to make your program consume more memory. Now call show_growth again:
>> my_leaky_func()
>> objgraph.show_growth(limit=10) # Stop and show change
This time it shows the difference between now and the last time you called it. Those extra objects are the problem.
Finally you need to find where the reference to those leaky objects is being held:
I recently finished Gary Noesner’s Stalling for Time: My Life as an FBI Hostage Negotiator, by the F.B.I.‘s former head of and founder of their hostage negotiation unit. The book is a great read (and I suspect heavily ghost-written). Here’s what I learnt:
Your goal as a negotiator is to get the target(s) (the person or people you are trying to arrest) to surrender peacefully to law enforcement.
Sometimes there are hostages, and then your priority is securing their release, but usually there are not. By getting them to put down their weapons and come out you are usually saving their lives, and also protecting your colleagues.
The last resort is an armed assault by the SWAT team. Prior to negotiation being taken seriously by law enforcement, this was the only option.
Make exclusive contact
First and foremost, you need to get in contact with them. Usually they are keen to talk, and most often you can use the phone line. Sometimes you have to get the SWAT team to bring them a field telephone. Sometimes you stand outside the window or at the foot of the stairs, and shout. And occasionally, as in the Beltway sniper case you have to ask the media to say things and hope the target hears.
After a while working with git, you end up with lots of branches, especially if you use git-flow inspired feature branches. Here’s one way to clean them up.
For any branch, I want to know whether it has been merged, when the last commit was, and ideally if the matching ticket in our tracker has been closed.
Switch to your main branch, usually develop or master: git checkout develop
List all the branches which have been fully merged into it:
For most Django apps, indeed most webapps, the bottleneck is the database. The biggest gains usually come from reducing the number of queries used, and adding database indexes. django-debug-toolbar helps a lot here. After that, caching and de-normalization also help reduce database queries.
But what if your app is CPU bound? How do you find out where it’s spending it’s time? It’s easy with the runprofileserver from django-extensions – here’s how:
In Python 2 you need to convert between encoded strings and unicode. It’s easy if you follow these three simple rules:
Decode all input strings
name = input_name.decode('utf8', 'ignore')
You need to decode all input text: filenames, file contents, console input, database contents, socket data, etc. If you are using Django, it already does this for you, as much as it can.
Auto packing the repository for optimum performance. You may also
run "git gc" manually. See "git help gc" for more information.
error: cannot lock ref 'HEAD (xyz's conflicted copy 2011-06-02)'
error: cannot lock ref 'refs/heads/master (xyz's conflicted copy 2011-06-02)'
error: failed to run reflog
You just need to delete the offending files from .git/logs/ and run your operation again.
The News International phone hacking scandal is the case of a British tabloid’s staff hacking into several thousand people’s voicemail, over a period of at least six years.
They listened to voicemail of the 7/7 terrorist attack victims, politicians, a murdered schoolgirl (including erasing some messages, leading the family to think she lived), the British Royal Family, various celebrities, and other journalists.
Internally the as_view method creates a new instance of your class (thereby making things thread-safe), and passes the __init__ method anything you passed to as_view.
Instead of over-riding dispatch you might prefer to use the get and post methods, which get called when you’d expect.
What had me confused initially, is that they are refered to as class-based generic views. Yes the generic views are implemented like this, and you may benefit from sub-classing one of those instead of the bare-bones View, but you don’t have to.
In the past few months, I’ve inherited two projects which used django-mptt, a toolkit for adding trees to Django models. Here’s my experience so far:
mptt is full of magic
That’s both good and bad. Good because it does a lot for you. Bad because it’s difficult to find out what that is. By becoming an MPTTModel you magically get four new database fields, tens of methods, and a whole new manager, grafted on to your model.
If you are an active user of Ubuntu’s notifications, for example via lintswitch you may of noticed that they have two key problems, which are easily solved:
They appear in a strange place, which you can’t change.
These days, for most internet businesses, the number one challenge is customer acquisition and marketing — not building a website. The overwhelming majority of startups that fail don’t fail because their website didn’t work. They fail because not enough people used it. This means that as entrepreneurs, we need to do a better job of vetting our markets before even building anything. It’s just too much of a waste to build out things that people don’t want.
The crux of her talk (the talk hasn’t happened yet, I’m extrapolating from the linked interview) looks to be that you probably don’t need to start building yet, and what that means is you don’t need a technical co-founder yet. You need to vet your market first. Here’s what she suggests:
Right now, for people like me who have access to servers, the single biggest benefit we can provide to society at large is by running a Tor relay. Tor provides anonymity to users of the Internet.
This page is about contributing to the network by running a relay (or server, or node – same thing). If you want to use Internet services anonymously, you probably want the Tor Browser Bundle.
There’s also general instructions on running a relay. Mine are specific to Ubuntu / Debian.
Ask people where they go to “get work done”, where they are at their most productive: They almost never say ‘the office’. Or if they do, it’s before or after hours.
Work is like sleep, it proceeds in cycles. You have to go through the light-sleep / light-work cycles to get to the meaty stuff. Every time you get woken up / interrupted, you start from scratch.
, by the 
Feed
RSS / Atom feed