Of course, people don’t come over to just sit/sleep on your couch, they want to see things!
That’s why I made a list of interesting things to see and do in the center of Antwerp. You’ll find the things on that list below with some added explanation and history for each item.
It might also come in handy when an other CouchSurfer comes over.

This is just a list of places and explanations, not a path you can follow.
Also, all prices listed here are the ones at the time of writing for adults without any sort of discount.
Antwerp has special discounts for many of it’s museums if your age is either <26 or >65 or you’re in a group. (-26 is often € 1 entrance)

All the locations mentioned below are pinned on a map which you can find here.

Map

View Sightseeing in Antwerp in a larger map

Museums

‘t MAS (Het Museum aan de Stroom)

Our newest museum. It’s a modern looking building which consists of a big staircase wrapped around a central column. The stairs are free to ascend and lead to the roof of ‘t MAS where you’ll have a good (but windy) view over the city. At every floor you’ll have the opportunity to enter the large central column which houses the museum’s collections. However, to be able to enter these rooms you’ll need an entrance pass which you can but at the ground level.

The museum houses a permanent and a temporary collection. The price to be able to enter both collections is € 10.
Address: Hanzestedenplaats 1

Diamond museum

Antwerp is sometimes called the diamond capital of the world. You’ll quickly notice this when you take a walk in the area around the central station. The area around the station is filled with jewelery shops, one right next to the other.
On one of the sides of the Astridplein in front of the station is the diamond museum. The museum describes the life of a diamond from the fresh mined rough glass rock to the cut jewel.

Entrance cost: € 6
Address: Koningin Astridplein 19

Middelheim Sculpture Museum

This museum, which lies outside the city limits and is partly an open-air museum, has a collection of modern and contemporary sculptures.
In total there are 480 sculptures, 280 medals and 600 sketches and prints.
A big part of the sculptures are spread out over a park of 25 hectares (62 acres) in size.

Entrance cost: Free
Address: Middelheimlaan 61

Onze-Lieve-Vrouwekathedraal

Without a doubt the most impressive and well known building in Antwerp. It’s the largest Gothic church in the Low Countries, built between 1352 and 1521.
Beside the abundance of sculpted artwork on the exterior of the building you can also find various works of art by famous artists, one of which Rubens, inside.

A lot of tourists come to visit Antwerp because of the story “A Dog of Flanders” . In the square in front of a cathedral, de Handschoenmarkt, is a plaque dedicated to it.
Also on de Handschoenmarkt is “Het Putje Van Quinten Massijs”, a well built in 1490.

Entrance cost:  € 5.
Address: Groenplaats 21

Plantijn-Moretus Museum

Museum of the Plantin and Moretus print shop. At it’s time (one of?) the biggest print shop of mainland Europe. Had 16 active printing presses at all times, for comparison, the largest print shop in France at that time had 4 presses.
The museum contains the oldest printing presses on the earth (around 1600).

Entrance cost: € 8
Address: Vrijdagmarkt 22-23

Rockoxhuis

Like the Rubenshuis, the Rockoxhuis is an excellent way to get an image of how the nobility lived around the end of the 16th, beginning of the 17th century here in Antwerp.
Nicolaas Rockox had various roles in Antwerp. He was elected councilor 7 times and mayor of external affairs for 8 times.
The house contains lots of paintings and authentic furniture.

Entrance is € 2,5.
Address

Rubenshuis

Peter Paul Rubens, a Flemish painter known world wide had his home and atelier right here in the center of Antwerp. Of course a big part of the things to see in the house are paintings he made himself or paintings he acquired of other painters but even if you’re not a paintings fan it could still be an interesting visit. The house gives you a good view of how the nobility lived in the 16th-17th century, especially the inner court of the house is astonishing.

Entrance is € 8.
Address: Wapper 9

Vleeshuis

In the middle ages a lot of professions had guild houses, het Vleeshuis (the meat house) was one of them. In this case it was the guild house of the butchers.
The building was constructed 50 years after ‘t Steen in 1250 to sell slaughtered animals. Currently the building is used as a museum containing 600 years of  history about music and dance.

Entrance costs € 5.
Address: Vleeshouwersstraat 38

Buildings & Places to see

‘t Steen

Het Steen was constructed at the beginning of the 13th century, between 1200 and 1225. This makes it the oldest building in the city.
Unfortunately part of the building was deconstructed in the 19th century when de Schelde was widened to expand the harbor of Antwerp. Currently only the front of the stronghold is still standing.

For a very long time the building was used as a prison (1307-1827). From 1952 the building was used as a maritime history museum which later moved to the newer MAS museum.

At the beginning of the walkway to the castle there is a statue called “de Lange Wapper”. The statue depicts a giant from Antwerp folklore.
De Lange Wapper can shapeshift and he uses this ability to trick people. A much used trick of his is to follow drunks home, constantly growing while following. Eventually when the drunk arrives home de Lange Wapper is so tall that he can peek through the top level windows of the drunk’s house.

Address: Suikerrui 7

Bourla Schouwburg

A theater with an impressive front built in 1834. It is still used as a theater by 2 theater groups.
Every Sunday and national holiday an extensive brunch buffet is hosted in the Schouwburg.

Address: Komedieplaats 18

Centraal Station

This station, a key stop between the Paris and Amsterdam, is considered one of the most beautiful train stations of the world.
Interesting parts of the building to view are the front of the building, the entrance hall and the glass dome over the top level of rails.

If the NMBS/B-Rail is not on strike you might be able to ride the train somewhere too.

Address: Koningin Astridplein 27 

Hendrik Conscience Plein & Carolus Borromeus kerk

On the square in front of the Carolus Borromeus kerk you’ll find a statue of the Flemish writer Hendrik Conscience, after whom the square was named when the statue was installed in 1880.
The interior of the church exists of marble, wood sculptures and paintings.

Address: Hendrik Conscienceplein 6-12

Koninklijk Museum voor Schone Kunsten (Royal Museum of Fine Arts)

Unfortunately the museum is closed for renovatuion until 2017.
But it does organize expositions in other places in and around Antwerp.
Where it hosts these you can see on it’s website.

Groenplaats

South of the cathedral is the Groenplaats. It’s surrounded by a few protected buildings, among which the building that currently houses the Hilton hotel.

Grote Markt

Like pretty much any larger European city Antwerp also has a Grote markt/Grand Place. It’s situated North West of the Cathedral. On de Grote Markt you will find Antwerp city hall, the statue of Brabo en Antigoon and surrounding the square, guild houses.

The statue is based on an old city legend.
There is a giant, Druon Antigoon, who demands toll of the people who want to cross de Schelde. If they couldn’t pay the toll he would cut of their hand. He was eventually slain by Silvius Brabo, spuuosedly the nephew of the roman emporor Julius Caesar. He gave him some of his own medicine and cut off his hand.
The statue depicts Silvius throwing away Antigoon’s severed hand.
According to another myth this is also where Antwerp has it’s name from. Hand werpen (Hand throwing) => Handwerpen => Antwerpen.

Each of the houses along the square belonged to a guild. Some of the houses have statues on the top of their roof which is in some way connected to the guild to which the house belonged.

Meir

De Meir is the largest shopping street of Antwerp and possibly of entire Belgium (She’s competing for the title with the Nieuwstraat in Brussels). Even if you’re not interested in shopping you should still walk it’s distance to take a look at the decorated buildings that surround it.
It also connects the old city center with the Rooseveltplaats (which is close to the central station) so you can easily go from one to another if you don’t mind a walk.

Stadsfeestzaal (City festivities hall)

At present this big hall with it’s decorated ceiling is being used as the central space of a shopping center.

Address: Hopland 31, Meir 78

Vlaaikensgang

De Vlaaikensgang is an alley which runs behind the backsides of some old medieval houses.
At about halfway in the Pelgrimsstraat you will find a gate leading to this alley. Look closely! It’s not very obvious.
Inside the Vlaaikensgang there are a few pittoresque spots.

Entrance point:  Oude Koornmarkt 16

Voetgangerstunnel (Sint-Annatunnel)

Antwerp is largely situated on the east bank (right side) of de Schelde. Across de Schelde the area is known as de Linkeroever.
Boths sides are connected by a pedestrian tunnel which dates back from 1933. Is it still widely used today.
The tunnel itself could be an interesting look because of it’s old wooden escalators and tiled interior.
Even if that can’t pique your interest, you have a nice view of the other side, especially at night when the city is lighted.

Address: Sint-Jansvliet

Zoo van Antwerpen

Maybe not very special when compared to other zoos, but there are some older buildings inside which might be interesting to see.
Pretty much anyone who has gone to school around Antwerp has visited the zoo multiple times on a school trip.

Entrance: €22
Address: Koningin Astridplein 26

Zurenborg

This Neighborhood is situated around de Dageraadplaats, a square with lots of cozy cafes and restaurants surrounding it. A bit further, after passing the Railroads is the Cogels-Osylei which has a lot of old beautiful mansions.

Food & Drink (Delicacies)

Désiré de Lille

Belgian Waffles are a worldwide known sweet snack but they are nothing compared to the other unhealthy goodnesses we have here. Most of them can be bought at stands on a so called Kermis or Foor (Carnival).
Unfortunately they travel around so it can be hard to know if there’s one close when you’re visiting Antwerp. Désiré de Lille is a snack restaurant / take out shop which has these snacks available all year round.
The original founder of the restaurant is also the inventor of the Lacquemant, a flat waffle with a syrup in it of which the recipe is a secret.

I highly recommend trying out the Laquemants and the Smoutebollen.
Address: Schrijnwerkersstraat 14

Het Elfde gebod

This cafe is right next to the cathedral. It’s walls are completely decorated with statues of various sizes. It’s not necessarily a must-see, but it’s more of a unique thing you won’t quickly find somewhere else.

Address: Torfbrug 10

De Pelgrom

This was an old storage space for valuable goods which has now been transformed to a cozy cafe.
Supposedly on weekends there is also a guide available at the entrance of the cafe who will guide you (for €3) through the house above the cellar which is decorated authentically.

Address: Pelgrimstraat 15

De Vagant

Jenever is the Dutch and Flemish vodka. We have them in all kinds of flavours and strengths.
The ideal spot to try them is de Vagant, which offers more than 150 varieties of them.

Address: Reyndersstraat 25.

Other delicacies

I’m sure you’ve heard of our chocolate and beer, which are all widely available in Antwerp.
But have  you tried our fries? Take this recommendation and go to a frituur once. Order a “puntzak” with (Belgian) mayonnaise. Yes, mayonnaise. If you’re from the US/Australia/..(?) I can assure you, our mayonnaise is a different sauce entirely. There is a good frituur cart near ‘t Steen.
From then on, start calling them Belgian fries instead of French fries please.

Events

Vrijdagmarkt

De Vrijdagmarkt, literally translated Friday market, is as the name says a market that is hosted every Friday (Vrijdag in Dutch) from 9:00-13:00 on the square called … Vrijdagmarkt.
On this market second hand goods ranging from clothing to furniture get sold. Often these goods are confiscated goods of people who defaulted on their bills.
Therefore there will most likely be an auctioneer yelling for bids. Below a video of the market in action.

Other suggestions found on the internet

Kassa 4: A student bar on de Ossemarkt.

Cafe de Muze: A jazzy bar on the Melkmarkt.

Caffénation: A coffee shop which offers all sorts of coffees created by all sorts of brewing methods.

Amadeus: A restaurant which offers an all you can eat menu for spare ribs.

‘t Waagstuk: Similar to De Vagant mentioned above, except  it’s variety is in beer. It offers a few hundred kinds of beer.

De Koninck brewery: A well known brewery in Antwerp, they offer a tour through the brewery.

Public transportation

Of course you’ll want to get around at an acceptable pace.
In the city center I recommend going by foot since everything is so close together anyway and otherwise you might miss out on the city life itself.

For longer distances (city to city) you can take the train, which is operated by B-rail (formerly NMBS).
For inside Antwerp itself you’re best off using the buses and trams(/metro), which are run by De Lijn.

I recently had some nasty trouble with my Galaxy SII.
The problem I was having was that after working normally the phone would suddenly act like I was pulling out and putting in the usb cable constantly.
The battery would indicate being charged, discharged and then charged again (etc.).
After shutting the phone down and trying to reboot it I would get an image showing the big battery image you get when charging the phone while it’s off.
A few seconds later it would also display an exclamation mark and a thermometer.

I tried letting the battery “cool” to no avail (It didn’t feel exceptionally warm to the touch anyway)
Switching to a different battery did seem to fix the problem, at least for a short while. A day later I was having the exact same symptoms. Time for some more Googling I thought.

Solution

Eventually I found this topic on Android Forums. The solution to my page was found on page 2.
Apparently even a small amount of dirt in the micro usb port can cause these problems.
It’s easily cleaned with a toothpick. To get in the thin space away from the battery you can split a toothpick with scissors.
You can dip the tip of the toothpick in rubbing alcohol  to get even the last bits of dirt.

If even this doesn’t work and you’re sure it’s the usb port (water damage maybe) the port itself is quite easily and cheaply (€15) replaced.
In the same topic someone did this and posted an image of the port’s package showing all the product info.
Also posted was a video showing how to disassemble and reassemble the phone.

I updated my SoundSwitch Application.
You can install it by going here.

The purpose of SoundSwitch is to be able to easily switch between  2 or more Audio output devices.
For example, I have a wireless headset and my regular speakers.
Both are detected as a separate audio card in the sound panel.
The only way to switch between them is to open the playback devices panel and select one of them and choose to put it as default device.

That’s such a hassle!
With SoundSwitch you just press Ctrl+Alt+F11 and it toggles between the cards you selected.

Todos:

1. Let the application start up when the user logs in. (currently you have to start it yourself)
2. Allow users to set their own shortcut (instead of  Ctrl+Alt+F11)
3. Make the configuration easier. (Won’t be possible I’m afraid though)

UPDATE:
Changed the hosting to CodePlex, apparently you can host ClickOnce applications there!

$.fn.scrollTo = function(duration){
    if(duration == null){
        duration = 1000;
    }
 
    var offset = $(this).offset().top - $(window).height()/2 + $(this).height();
    $('html,body').animate({
       scrollTop: offset
    }, duration);
}

This small plugin will scroll to a selected element when calling .scrollTo() on it.
It has an optional parameter which specifies the duration of the scroll.

For example, if i would have a div with the id “#mydiv” I would let the screen scroll to it using this code:

$('#mydiv').scrollTo();
 
//Or, if you want the animation to be slower
$('#mydiv').scrollTo(2000);

The top of the selected element will be displayed at 50% of the screen unless the scrollbar is too short, then the element will be lower on the screen.

I also have to keep track of what’s in my fridge and what’s expiring when.
I suck at that.
However, I’m good with computers. And computers are good at keeping track of stuff.
So I created a small tool to do just that, Fridgemon.

I know it’s butt-ugly but it does it’s job.

Textbooks

Full fledged learning tools containing a textbook explaining grammar and spelling rules, audio tapes for pronunciation and often also workbooks to apply the acquired knowledge.

Pimsleur Norwegian

30 audio lessons of 30 minutes each. I started learning with this. After each lesson of Pimsleur’s completed I could clearly notice that I had learned something. The rate at which I learned stuff using Pimsleur is very high. Unfortunately Pimsleur Norwegian has only 1 level of lessons, compared to 2 or 3 levels for larger languages like French or Chinese. If I had to suggest a starting point to learning Norwegian, this would be it. Pimsleur Norwegian website

Ny I Norge & Bo I Norge

Ny I Norge contains a textbook, audio readings of the conversations in the textbook, a workbook and listening comprehension exercises. Bo I Norge is a textbook for more advanced learners (after Ny I Norge). This will be the second resource I’ll be using, after Pimsleur.

Colloquial Norwegian

Similar to Ny I Norge, consists of a textbook with exercises and audio readings. I do have the impression that the learning curve of the book is higher.

På vei, Stein På Stein, Her på berget

All three books consist of a textbook, a workbook and audio files. They consist of three levels of which På vei is the 1st, Stein På Stein the second and finally Her på berget the third. Each of the books have free exercises online. (På vei, Stein På Stein, Her på berget)

Praktisk Norsk I & II

From the same series as På vei etc. Also has free exercises online here and here.

Teach Yourself Norwegian

A book with conversations both in English and in Norwegian. Seems to rely heavily of cross referencing the dialogues in both languages. Also contains audio recordings for the conversations.

Sett i gang I & II

A textbook, workbook and audio files. The audio files are freely downloadable here and here.

My Little Norway

A blog about 2 people in Norway, one native speaker and one who’s learning Norwegian. They also have a bunch of lessons on the blog for learning Norwegian.

Assimil (for German or French speakers)

Norwegisch ohne Mühe (For German speakers) | Assimil site Le Norvegien sans Peine(For French speakers)

Television

NRK

NRK is the Norwegian national broadcaster. A lot of the programs are visible freely (Click A-Å on the top and choose a starting letter of a program). For example, the newsis something that is updated daily.

NRK Torrents

NRK also offers some HD torrents of their programs. These don’t get updated very often I’ve noticed.

TV3

TV3 broadcasts more foreign (to Norway) programs which are more limited by drm. But those are most likely not the programs you want to watch anyways cause they are in different languages :) Watch out, they also have some Swedish programs.

TVNorge (NOT FREE)

TV2 (SEMI-FREE)

Only short clips of programs are free, full programs require a subscription.

Radio

• Radio Norge
• NRK P1 – Click the small red round button with the play icon to the right
• NRK P2 – Click the small red round button with the play icon to the right
• NRK Petre (P3)
• NRK Alltid nyheter (always news) – Click “Nettradio” in the left bar.
• NRK Klassisk
• P4 Radio Hele Norge – Click “lytt nå”
• All NRK Radio channels
• A huge list of other norwegian radio channels

Extra resources

Anki flashcards

Anki is a program to exercise flashcards using spaced repetition. I use this to exercise vocabulary. The great thing about Anki is that you can also add audio files to your flashcards, so you can train pronunciation and spelling in one go. I don’t like having to record every word manually, so I made this site to automatically generate sound files for words you type in. Here is a list of the 1000 most used Norwegian words to get you started. Be sure to use Bokmål (see below).

News in “Simple Norwegian”

Klar Taleis a news website written in simple Norwegian. If you use their website together with a browser plugin which can translate (unknown) words you select then this is another good way of learning.

Lessons on Youtube

Crienexzyon Youtube has a bunch of videos on Norwegian pronunciation. She’s also a fine example of Scandinavian beauty.

Films

A great way to passively (but slowly) learn is by watching movies and series. Some Norwegian films I liked were:

• Vegas
• Trolljegeren
• Død snø
• Fritt Vilt I, II, III

A big list of Norwegian films can be found on IMDB.

Livemocha

Livemocha uses the same teaching style as Rosetta Stone. I’m not particularly fond of this way of learning, I learned a bunch more by just a few lessons of Pimsleur. However, it’s a great way to find native speaking partners.

Interpals

A site aimed at bringing penpals together. Has quite a large user base.

Linguistic tools & sound files of Norwegian dialects

This site contains a tool to break down sentence structure and some sound files of texts in various Norwegian dialects. I think it should be accessible  through this site as well, but that one seems to have some database problems atm. Books about norwegian dialects can be found here.

Free music

Gatas Parlament is a Norwegian rap group and they offer their music for free on their website.

More info

This sitehas a bunch of links to Norwegian related things.

Bokmål & Nynorsk

Norwegian has 2 written forms, Bokmål and Nynorsk. Unlike what Nynorsk’s (new-Norwegian) name seems to suggest it is actually older than Bokmål. The grand majority of (newly) written material is in Bokmål, so you’ll have the most use of learning Bokmål. As far as I know, all textbooks listed above use Bokmål.

Get started

I found a torrent which contains a lot of the resources mentioned above. Credit where credit is due: a lot of the resources mentioned here came from this post on reddit. Update Found a site with good explanations on grammar rules. And a site which will show you ALL conjugations of a given verb! Super useful.

Bulktts allows you to choose a language, paste your list of words in and download a zip file with the mp3′s.

There are still some bugs though, at the moment words with special characters won’t product the correct sound.
Update: Sound bug fixed. Only the filenames for special character words in zip files are still not correct.

After a bit of googling around I came to this StackOverflow answer.
That worked like a charm, and here is my more reusable version:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

from zipfile import ZipFile
from StringIO import StringIO
 
class InMemoryZipFile(object):
	def __init__(self):
		self.inMemoryOutputFile = StringIO()
 
	def write(self, inzipfilename, data):
		zip = ZipFile(self.inMemoryOutputFile, 'a')
		zip.writestr(inzipfilename, data)
		zip.close()
 
	def read(self):
		self.inMemoryOutputFile.seek(0)
		return self.inMemoryOutputFile.getvalue()
 
	def writetofile(self, filename):
		open('out.zip', 'wb').write(self.read())

Save as “inmemoryzip.py” and import it as “inmemoryzip”.
This is quite limited compared to the standard ZipFile class, but this gets the job done for what I needed it.

You start with a population of begin states and each state has a ‘fitness’ which indicates how close it is to a solution.
Based on that fitness you will crossjoin or mate 2 states. Higher fitness = higher chance of mating.

I implemented the example given in my AI course’s slides in python.
The example is trying to find a solution to solve an n-queens problem, in this case 8 queens on an 8×8 chessboard.
Briefly explained: you need to place 8 queens on a chessboard so that none of the queens can attack eachother.
(A queen can move like a Bishop and a Tower, horizontally and diagonally)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104

from __future__ import division
from random import Random, random
 
class State(object):
	MUTATION_RATE = 0.03
	def __init__(self, parents=None):
		r = Random()
		self._fitness = None
		self._probability = None
		if parents==None:
			self.state = [r.randint(1,8) for y in range(8)]
		else:
			parent1 = parents[0]
			parent2 = parents[1]
			self.state = self.crossover(parent1, parent2)
			self.mutate()
 
	def fitness(self):
		if not self._fitness:
			state = self.state
			horizontal_collisions = sum([state.count(col)-1 for col in state])/2
 
			diagonal_collisions = 0
			for i, col in enumerate(state):
				for j, diagonal in enumerate(state):
					mod = abs(i-j)
					if mod > 0: #we don't want to count the current queen in a collision with herself
						if diagonal + mod == col or diagonal - mod == col:
							diagonal_collisions += 1
			diagonal_collisions /= 2 #we were counting the diagonal collisions double
			self._fitness = int(28 - (horizontal_collisions + diagonal_collisions))
		return self._fitness
 
	def probability(self, population):
		if not self._probability:
			self._probability = self.fitness() / sum([x.fitness() for x in population])
		return self._probability
 
	def crossover(self, parent1, parent2):
		r = Random()
		crossover_index = r.randint(0,8)
		left = parent1.state[0:crossover_index]
		right = parent2.state[crossover_index:8]
		left.extend(right)
		return left
 
	def mutate(self):
		r = Random()
		for i in range(len(self.state)):
			if random() < State.MUTATION_RATE:
				self.state[i] = r.randint(1,8)
 
	def __str__(self):
		r = ''
		r += '   '
		for i in range(8):
			r += '%d ' % (i+1)
		r += '\n  ' + '--'*8 + '\n'
 
		for i in range(8,0,-1):
			r += '%d|' % i
			for j, queen in enumerate(self.state):
				if queen == i:
					r += ' O'
				else:
					r += '  '
			r += '|\n'
		r += '  ' + '--'*8 + '\n'
		print self.fitness()
		return r
 
def pickRandomByProbability(populationByProbability):
	i = 0
	selectedState = None
	while selectedState == None:
		current = populationByProbability[i]
		if current[0] <= random():
 			return current[1]
 		if i+1 >= len(populationByProbability):
			i = 0
		else:
			i += 1
 
def generateNextPopulation(population, n):
	newPopulation = []
	while len(newPopulation) < n:
 		populationByProbability = [(x.probability(population), x) for x in population]
 		parent1 = pickRandomByProbability(populationByProbability)
 		populationByProbability = [x for x in populationByProbability if x[1] != parent1]
 		parent2 = pickRandomByProbability(populationByProbability)
 		newPopulation.append(State((parent1, parent2)))
 	return newPopulation
 
if __name__ == '__main__':
 	populationSize = 100
 	generation = 1
 	population = [State() for x in range(populationSize)]
 	while not 28 in [x.fitness() for x in population]:
 		print "generation %d\tMax fitness: %d" % (generation, max([x.fitness() for x in population]))
 		population = generateNextPopulation(population, populationSize)
 		generation += 1
 	for x in population:
 		if x.fitness() >= 28:
			print x

State

The State class keeps track of a state. In this case that is a list of 8 integers ranging from 1 to 8.
Each integer represents the position of a queen in a column (which row).
Since queens can attack vertically each queen has to be in a different column by default.

Fitness

A collision is two queens who are able to attack each other. This means they are in the same diagonal, the same row or the same column.
The maximum amount of collisions that can occur is 28. The fitness function is a higher-is-better function, so we calculate it by substracting the amount of collisions that occur in the current state from 28.
A solution would have 0 collisions and thus a fitness of 28.

Probability of mating

When we generate the next population of states we will need to have something on which we can base which 2 states can ‘mate’.
We want only the best states (the one closest to a solution) to mate, so the best heuristic to define the chance of a state being allowed to mate is it’s fitness.

Crossover (mating), mutation

When we crossover 2 states we choose a point in the states where we will ‘chop’ them in 2 parts.
We will for example take the left 3 columns of the 1st parent and the 5 last of the second parent.
The child state is then the combination of these columns.
We don’t want to stay stuck in the same state pool because what if the initially randomly generated population has no queen in row 3?
We would never be able to get a solution because a solution requires a queen in each row.
No matter how many times we crossover 2 states, we will never get a state in row 3.
Therefore we need to include a random mutation when crossing over 2 parents.
Each column in the child state has a specific percentage chance of changing it’s value to a random number from 1 to 8.

Conclusion

I’ve noticed that this doesn’t find a solution as fast as I initially expected. It can quickly take over a few (ten)thousand generations before a solution is found.
I haven’t noticed any noticeable speed increase in finding a solution when taking a population of 100, 1000 or 10000. (Didn’t do any benchmarks, just a few runs per population size)
Maybe a solution would be found more quickly if the percentage chance of mating weren’t on a linear scale but an exponential one.
I’m not sure if i’m expressing this correctly but what I mean is that the chance of mating for bad fitnesses and good ones is currently too close. Good ones should be picked way easier than bad ones. Now the chance differs only by a few percent or even a few tenths of a percent depending on the size of the population.

Setting some settings

First of all, set your application id to whatever you called your application in the GAE dashboard.
Open up app.yaml in the root folder and change what’s behind “application: “.
This isn’t a requirement to be able to develop for GAE, but if you want to deploy your app this will need to be set.

Open up settings.py. If you want to use sessions in your application you’ll need to uncomment “django.contrib.sessions.middleware.SessionMiddleware” in MIDDLEWARE_CLASSES near the end of the file.

If you’re planning on using GAE’s memcache you’ll need to add the following lines to MIDDLEWARE_CLASSES:

'django.middleware.cache.UpdateCacheMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.cache.FetchFromCacheMiddleware',

And you’ll need to set these variables as well:

CACHE_BACKEND = 'memcached://?timeout=0'
CACHE_MIDDLEWARE_SECONDS = 0

CACHE_MIDDLEWARE_SECONDS sets the default caching time in seconds for each page. Since I don’t want every page to be cached by default I’ve set this value to 0.
Note that the setting of the cache info is different in Django 1.3. (I’m using 1.2.4 here)

Then at the bottom in INSTALLED_APPS add a line with the name of the app we’ll be creating.
In the tutorial they’re using the name “polls”, so that’s what i’ll call it as well.

This is how my settings file looks now.
And that’s all the settings that we need to set. The database (Google’s BigTable) settings have already been taken care of by the helper.

Creating the application and creating models

Open a command prompt and cd to where manage.py is situated. (in the root folder of the project)
Type “python manage.py startapp polls”. or replace polls by whatever name you set in INSTALLED_APPS.

The models we’ll be creating won’t extend from the standard Django base model but instead will use the base class provided by the helper. This is an edited version of the Django base model class that is compatible with the GAE datastore.

models.py:

1
2
3
4
5
6
7
8
9
10
11

from appengine_django.models import BaseModel
from google.appengine.ext import db
 
class Poll(BaseModel):
    question = db.StringProperty()
    pubDate = db.DateTimeProperty()
 
class Choice(BaseModel):
    pollId = db.IntegerProperty()
    choice = db.StringProperty()
    votes = db.IntegerProperty()

Notice that there are no foreign keys, this is because GAE is a non-relational data store. Foreign keys don’t exist.

Views and templates

We’ll need 3 pages:

1. Create  a poll
2. List existing polls
3. View a specific poll and be able to vote on one of it’s choices

My urls.py file is as follows:

1
2
3
4
5
6
7

from django.conf.urls.defaults import *
 
urlpatterns = patterns('',
	(r'^$', r'polls.views.list'),
	(r'^create$', r'polls.views.create'),
	(r'^view/(\d+)$', r'polls.views.view'),
)

The views:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38

from django.shortcuts import render_to_response
from django.http import HttpResponse, HttpResponseRedirect
from polls.models import Poll, Choice
from datetime import datetime
 
def create(request):
	if request.POST:
		question = request.POST["question"]
		c1 = request.POST["choice1"]
		c2 = request.POST["choice2"]
		c3 = request.POST["choice3"]
 
		poll = Poll(question=question, pubDate=datetime.now())
		poll.save()
		choice1 = Choice(pollId=poll.key().id(), choice=c1, votes=0)
		choice2 = Choice(pollId=poll.key().id(), choice=c2, votes=0)
		choice3 = Choice(pollId=poll.key().id(), choice=c3, votes=0)
		choice1.save()
		choice2.save()
		choice3.save()
		return HttpResponseRedirect('/')
	else:
		return render_to_response('create.html')
 
def list(request):
	polls = Poll.objects.all()
	return render_to_response('list.html', {'polls':polls})
 
def view(request, id):
	if request.POST:
		choiceId = int(request.POST["voteChoice"])
		choice = Choice.get_by_id(choiceId)
		choice.votes += 1
		choice.save()
	id = int(id)
	poll = Poll.get_by_id(id)
	choices = Choice.objects.all().filter('pollId =', id)
	return render_to_response('view.html', {'poll':poll, 'choices':choices})

The templates:

list.html

1
2
3
4
5
6
7
8

<ul>
 {% for poll in polls %}
 <li>
 <a href="/view/{{poll.key.id}}">{{poll.question}}</a> - {{poll.pubDate}}
 </li>
 {% endfor %}
</ul>
<a href="/create">Create new poll</a>

view.html

1
2
3
4
5
6
7
8
9
10
11
12
13

<h1>{{poll.question}}</h1>
 
<form action="/view/{{poll.key.id}}" method="post">
 <ul>
 {% for choice in choices %}
 <li>
 <input name="voteChoice" type="radio" value="{{choice.key.id}}">
 {{choice.choice}} ({{choice.votes}} votes)
 </li>
 {% endfor %}
 </ul>
 <input type="submit" value="Vote" />
</form>

create.html

1
2
3
4
5
6
7
8
9
10
11

<h1>Create poll</h1>
 
<form action="/create" method="post">
 Question: <input type="text" name="question" /><br>
 
 Choice 1: <input type="text" name="choice1" /><br>
 Choice 2: <input type="text" name="choice2" /><br>
 Choice 3: <input type="text" name="choice3" /><br>
 
 <input type="submit" value="Create" />
</form>

I think everything is quite clear when you look it over.
There are a few differences with regular Django code, for example the filter line.

A zip file with the files of the project can be found here.

Update:  You might also be interested in checking out Django-nonrel which is a different way of running Django on GAE. It seems to be more flexible at first glance than the helper but I can’t say for sure since I haven’t used it yet.