Accessing a two dimensional array in Django template

Question

I am building a betting app where users can bet on different games. I want to show users' bets for different games in a table such as one as below:

game #   |   user 1   |   user 2   |   user 3

game 1  |   XXXX    |   XXXX    |   XXXX

game 2  |   XXXX    |   XXXX    |   XXXX

game 3  |   XXXX    |   XXXX    |   XXXX

...

here's my view

users = User.objects.all()
games = Game.objects.all()
bets = Bet.objects.all()

user_bets = [[] for i in range(len(games))]

for i, game in enumerate(games):
    game_bets = bets.filter(game=game)
    for usr in users:
        user_bet = game_bets.filter(user=usr)[0]
        user_bets[i].append(user_bet)

data = {'games', games, 'users', users, 'user_bets': user_bets}
return render(request, 'bets.html', data)

But I don't know how to fill in the table using the 2d array user_bets. Any suggestions? Or if I'm doing the whole thing wrong any best practice to pass such data to template in Django?

Cheers

Answer 1

Passing Multi-dimensional arrays to templates in django is not straight forward. I've been working on this problem for a while, so I know your question is old, but for the betterment of django society, here's what I've finally worked out...

users = User.objects.all()
games = Game.objects.all()
bets = Bet.objects.all()

user_bets=[]
game_title=[]

for i, game in enumerate(games):
    game_titles = [game.title]
    game_bets = bets.filter(game=game)
    for usr in users:
        user_bet = game_bets.filter(user=usr)[0]
        user_bets[i][usr.id]=user_bet
data = {'game_titles', game_titles 'users', users, 'user_bets': user_bets}
return render(request, 'bets.html', data)

You then want to define two template filters, which for ease can live in your views.py

@register.filter
def index(List, i):
    return List[int(i)]

@register.filter
def entry_num_array(List):
    return range(len(List))

Then in your template

{% for bet in user_bets %}
{{ game_titles|index:forloop.counter0}}:
    {% for counter in entry|entry_num_array %}
        {{entry|index:counter}}|
    {% endfor %}
    <br>                
{% endfor %}