django-orchestra/orchestra/models/queryset.py

22 lines
678 B
Python

def group_by(qset, *fields, **kwargs):
""" group_by iterator with support for multiple nested fields """
ix = kwargs.get('ix', 0)
if ix is 0:
qset = qset.order_by(*fields)
group = []
first = True
for obj in qset:
current = getattr(obj, fields[ix])
if first or current == previous:
group.append(obj)
else:
if ix < len(fields)-1:
group = group_by(group, *fields, ix=ix+1)
yield previous, group
group = [obj]
previous = current
first = False
if ix < len(fields)-1:
group = group_by(group, *fields, ix=ix+1)
yield previous, group