When value is a list it should be returned as is

[tony13tv]

This change should help close #1103

[codecov-io]

Codecov Report

Merging #1340 (4c4d3f6) into main (b1e37af) will decrease coverage by 0.07%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##             main    #1340      +/-   ##
==========================================
- Coverage   99.44%   99.36%   -0.08%     
==========================================
  Files          15       15              
  Lines        1265     1267       +2     
==========================================
+ Hits         1258     1259       +1     
- Misses          7        8       +1     

Impacted Files	Coverage Δ
django_filters/widgets.py	99.37% <50.00%> (-0.63%)	⬇️

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[carltongibson]

Hi thanks. All changes need to include a regression test.

[Przemek625]

@tony13tv @carlosgoce This change wont help because

value = super().value_from_datadict(data, files, name)
will execute following code

value = data.get(name)
where data is a QueryDict and thus for list it will return only last value

https://stackoverflow.com/a/39565140/6645337

this code helped me to achieve query in form /?param=1&param=2

from django_filters.fields import BaseCSVField
from django_filters.widgets import QueryArrayWidget

class MyBaseCSVField(BaseCSVField):
    base_widget_class = QueryArrayWidget


class MyBaseInFilter(df.BaseInFilter):
    base_field_class = MyBaseCSVField


class NumberInFilter(MyBaseInFilter, df.NumberFilter):
    pass


class MytFilter(df.FilterSet):
    id = NumberInFilter()