[ADD] ATTENDANCE: Group by method updation

attendance/methods/group_by.py

@@ -0,0 +1,40 @@
+"""
+group_by.py
+
+This module is used to make queryset by grups
+"""
+from django.db import models
+
+
+def group_by_queryset(queryset, group_field):
+    """
+    This method is used to make group by field for the queryset
+    """
+    fields_split = group_field.split("__")
+    model = queryset.model
+    is_fk_field = isinstance(getattr(model, group_field, None), models.ForeignKey)
+    model_copy = model
+    field_obj = None
+    for field in fields_split:
+        field_obj = model_copy._meta.get_field(field)
+        model_copy = field_obj.__dict__["related_model"]
+
+    if fields_split or is_fk_field:
+        groupers = model_copy.objects.all()
+        groups = [
+            {
+                "grouper": grouper,
+                "instances": len(queryset.filter(**{group_field: grouper.id})),
+            }
+            for grouper in groupers
+        ]
+    else:
+        groupers = set(queryset.values_list(group_field, flat=True))
+        groups = [
+            {
+                "grouper": grouper,
+                "instances": queryset.filter(**{group_field: grouper}),
+            }
+            for grouper in groupers
+        ]
+    return groups