Refactor code quality issues (#2001)

src/pretix/control/forms/item.py

@@ -337,7 +337,7 @@ class ItemCreateForm(I18nModelForm):
                 setattr(self.instance, f, getattr(self.cleaned_data['copy_from'], f))
         else:
             # Add to all sales channels by default
-            self.instance.sales_channels = [k for k in get_all_sales_channels().keys()]
+            self.instance.sales_channels = list(get_all_sales_channels().keys())
 
         self.instance.position = (self.event.items.aggregate(p=Max('position'))['p'] or 0) + 1
         instance = super().save(*args, **kwargs)

src/pretix/control/permissions.py

@@ -7,7 +7,7 @@ from django.utils.translation import gettext as _
 
 
 def current_url(request):
-    if len(request.GET):
+    if request.GET:
         return request.path + '?' + request.GET.urlencode()
     else:
         return request.path

src/pretix/control/views/event.py

@@ -1363,7 +1363,7 @@ class QuickSetupView(FormView):
                 tax_rule=tax_rule,
                 admission=True,
                 position=i,
-                sales_channels=[k for k in get_all_sales_channels().keys()]
+                sales_channels=list(get_all_sales_channels().keys())
             )
             item.log_action('pretix.event.item.added', user=self.request.user, data=dict(f.cleaned_data))
             if f.cleaned_data['quota'] or not form.cleaned_data['total_quota']: