fix importerror on django 4

Author: tovmeod

admin_numeric_filter/forms.py

@@ -1,22 +1,24 @@
 from django import forms
-from django.forms import Media
-from django.utils.translation import gettext_lazy as _
-
-
-NUMERIC_FILTER_CSS = 'css/admin-numeric-filter.css'
+try:
+    from django.utils.translation import ugettext_lazy as _  # until django 3.2
+except ImportError:
+    from django.utils.translation import gettext_lazy as _  # from django 4
 
 
 class SingleNumericForm(forms.Form):
     def __init__(self, *args, **kwargs):
         name = kwargs.pop('name')
         super().__init__(*args, **kwargs)
 
-        self.fields[name] = forms.FloatField(label='', required=False,
-            widget=forms.NumberInput(attrs={'placeholder': _('Value')}))
+        self.fields[name] = forms.FloatField(label='', required=False, 
+            widget=forms.NumberInput(attrs={'placeholder': _('Value')}))        
 
-    @property
-    def media(self):
-        return super().media + Media(css=[self.NUMERIC_FILTER_CSS])
+    class Media:
+        css = {
+            'all': (
+                'css/admin-numeric-filter.css',
+            )
+        }
 
 
 class RangeNumericForm(forms.Form):
@@ -26,14 +28,17 @@ def __init__(self, *args, **kwargs):
         self.name = kwargs.pop('name')
         super().__init__(*args, **kwargs)
 
-        self.fields[self.name + '_from'] = forms.FloatField(label='', required=False,
+        self.fields[self.name + '_from'] = forms.FloatField(label='', required=False, 
             widget=forms.NumberInput(attrs={'placeholder': _('From')}))
-        self.fields[self.name + '_to'] = forms.FloatField(label='', required=False,
+        self.fields[self.name + '_to'] = forms.FloatField(label='', required=False, 
             widget=forms.NumberInput(attrs={'placeholder': _('To')}))
 
-    @property
-    def media(self):
-        return super().media + Media(css=[self.NUMERIC_FILTER_CSS])
+    class Media:
+        css = {
+            'all': (
+                'css/admin-numeric-filter.css',
+            )
+        }
 
 
 class SliderNumericForm(RangeNumericForm):