Question

I need some help with my problem. I have created a list of all my investments but now I need to seperate them by financial institution. I am trying to print a report out that will have all the investments for each financial institution on a seperate page but I am having trouble splitting them up.

For example what I want is:

TD Bank
– all investments for TD from my query

• next page –

Scotia Bank
-all investments for Scotia from my query

etc

The following is my views.py that has the query and adding all the information to my list.

Can anyone help me find a way to split it up so I can have them seperated by financial institution?

def confirmations_report(request, *args, **kwargs):
from investments.models import Investment, InvestmentManager
from reports.forms import ConfirmationsForm
import ho.pisa as pisa
import cStringIO as StringIO
import os.path
confirm_letter_list = []
context = {}

if request.POST:
    form = ConfirmationsForm(request.POST)
    if form.is_valid():
        start_date = form.cleaned_data['start_date']
        end_date = form.cleaned_data['end_date']
        investments = Investment.objects.all().filter(contract_no = "",maturity_date__range=(start_date, end_date)).order_by('financial_institution')
        for i in investments:
            confirm_letter_list.append({
                'fi':i.financial_institution,
                'fi_address1': i.financial_institution.address1,
                'fi_address2': i.financial_institution.address2,
                'fi_city': i.financial_institution.city,
                'fi_prov': i.financial_institution.state_prov,
                'fi_country': i.financial_institution.country,
                'fi_postal': i.financial_institution.postal,
                'primary_owner': i.plan.get_primary_owner().member,
                'sin': i.plan.get_primary_owner().member.client.sin,
                'type': i.product.code,
                'purchase_amount': i.amount,
                'purchase_date': i.start_date,
            })
            context['confirmlist'] = confirm_letter_list
        context['inv'] = investments
    if request.POST.has_key('print_report_submit'):
        context['show_report'] = True
        context['mb_logo'] = os.path.join(os.path.dirname(__file__), "../../../media/images/mb_logo.jpg")
        html = render_to_string('reports/admin/confirm_report_print.html', RequestContext(request,context))
        result = StringIO.StringIO()
        pdf = pisa.pisaDocument(StringIO.StringIO(html.encode("ISO-8859-1")), result)
        response = HttpResponse(result.getvalue(), mimetype='application/pdf')
        response['Content-Disposition'] = 'attachment; filename=unreceived-confirmations.pdf'
        return response

else:
    form = ConfirmationsForm()

context['form'] = form
return render_to_response('reports/admin/confirm_report.html', RequestContext(request, context))

Answer 1

Use a defaultdict with a list.

from collections import defaultdict
my_list = defaultdict(list)
for i in investments:
   my_list[i.financial_institution].append({ ... })

Here is how you would use it:

{% for i in my_list.iteritems %}
   Institution : {{ i.0 }}
   {% for z in i|slice:"1:" %}
     Total Items for {{ i.0 }} : {{ z|length }}
     {% for d in z }}
        {{ d.fi_address1 }}
        ....
     {% endfor %}
   {% endfor %}
{% endfor %}

Here is a simplified example:

>>> from collections import defaultdict
>>> d = defaultdict(list)
>>> d['hello'].append({1:'One', 2:'Two'})
>>> for i in d.iteritems():
...    print i[0]
...    for z in i[1:]:
...     print z
... 
hello
[{1: 'One', 2: 'Two'}]

As you can see the inner loop contains the list of dicts that you have added, so you need to adjust your loop logic accordingly.