如何在没有 model 的情况下使用 forms.py 创建 Django 下拉表单？

Question

I need to create a simple presentation filter for a Django webpage. Since it's discarded without need for storage, I do not need to use Model overhead.

Here is my relevant views.py code:

@login_required()
def cards(request):
    # form = CountryForm()
    f_name = STAT_FILES / 'csv/segment_summary_quart.csv'
    # pathname = os.path.abspath(os.path.dirname(__file__))
    df = pd.read_csv(f_name, index_col=None)

    pl_name = STAT_FILES / 'pickles/lbounds'
    pu_name = STAT_FILES / 'pickles/ubounds'
    lbounds = pickle.load(open(pl_name, "rb"))
    ubounds = pickle.load(open(pu_name, "rb"))

    filter_name = []
    i = 0
    max_i = len(ubounds)
    while i < max_i:
        filter_name.append(f'Personal best trophy range: {str(int(lbounds[i])).rjust(4," ")}-{str(int(ubounds[i])).rjust(4," ")}')
        i += 1

    sort_name = []
    sort_name.append("Alphabetic Order")
    sort_name.append("Most Popular")
    sort_name.append("Least Popular")
    sort_name.append("Highest Win Rate")
    sort_name.append("Lowest Win Rate")

    form = cardStatsForm(filter_name, sort_name)

Given that my values may change dynamically, I am trying to establish the cardStatsForm() object without initially knowing the values that will occur when publishing the page to the end user. The following code resides within forms.py:

from django import forms


class cardStatsForm(forms.Form):
    def __init__(self, filter_opts, sortOrder, *args, **kwargs):
        super(cardStatsForm, self).__init__(*args, **kwargs)
        self.fields['filts'].choices = filter_opts
        self.fields['sorts'].choices = sortOrder

    filts = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple, choices=(), required=True)
    sorts = forms.Select(choices=())

Unfortunately I haven't had to worry about the html side yet since I keep getting the following error with respect to my form class:

KeyError at /clashstats/cards/
'sorts'
Request Method: GET
Request URL:    http://127.0.0.1:8000/clashstats/cards/
Django Version: 4.0
Exception Type: KeyError
Exception Value:    
'sorts'
Exception Location: /Users/cooneycw/PycharmProjects/The6ix/clashstats/forms.py, line 8, in __init__
Python Executable:  /Users/cooneycw/miniforge3/envs/The6ix/bin/python

I am more familiar with the flask framework and see that Django relies more heavily on objects which I am less familiar with. What am i doing incorrectly here?

Answer 1

The solution recommend by AMG above enabled me to move past this error. The next error related to the expectation for tuples for the choice listings. The following code modified to send zipped tuples for the list items now completes successfully:

forms.py

from django import forms


class cardStatsForm(forms.Form):
    def __init__(self, filterList, sortList, *args, **kwargs):
        super(cardStatsForm, self).__init__(*args, **kwargs)
        self.filts = []
        self.sorts = []
        self.fields['filts'].choices = filterList
        self.fields['sorts'].choices = sortList

    filts = forms.MultipleChoiceField(widget=forms.CheckboxSelectMultiple, choices=(), required=True)
    sorts = forms.ChoiceField(choices=())

views.py

@login_required()
def cards(request):
    # form = CountryForm()
    f_name = STAT_FILES / 'csv/segment_summary_quart.csv'
    # pathname = os.path.abspath(os.path.dirname(__file__))
    df = pd.read_csv(f_name, index_col=None)

    pl_name = STAT_FILES / 'pickles/lbounds'
    pu_name = STAT_FILES / 'pickles/ubounds'
    lbounds = pickle.load(open(pl_name, "rb"))
    ubounds = pickle.load(open(pu_name, "rb"))

    filter_name = []
    i = 0
    max_i = len(ubounds)
    while i < max_i:
        filter_name.append(f'Personal best trophy range: {str(int(lbounds[i])).rjust(4," ")}-{str(int(ubounds[i])).rjust(4," ")}')
        i += 1
    filter_id = range(len(filter_name))
    filter_list = list(zip(filter_id, filter_name))

    sort_name = []
    sort_name.append("Alphabetic Order")
    sort_name.append("Most Popular")
    sort_name.append("Least Popular")
    sort_name.append("Highest Win Rate")
    sort_name.append("Lowest Win Rate")

    sort_id = range(len(sort_name))
    sort_list = list(zip(sort_id, sort_name))

    form = cardStatsForm(filter_list, sort_list)

My thanks to https://stackoverflow.com/users/4872140/amg for his help to resolve this issue.