39 lines
1.1 KiB
Python
39 lines
1.1 KiB
Python
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def group_by(qset, *fields):
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""" group_by iterator with support for multiple nested fields """
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def nest(objects, ix):
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objs = []
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result = []
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first = True
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for obj in objects:
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current = getattr(obj, fields[ix])
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if first or current == previous:
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objs.append(obj)
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else:
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if ix < len(fields)-1:
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objs = nest(list(objs), ix+1)
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result.append((previous, objs))
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objs = [obj]
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previous = current
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first = False
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if ix < len(fields)-1:
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objs = nest(list(objs), ix+1)
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result.append((current, objs))
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return result
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objs = []
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first = True
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for obj in qset.order_by(*fields):
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current = getattr(obj, fields[0])
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if first or current == previous:
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objs.append(obj)
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else:
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if len(fields) > 1:
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objs = nest(objs, 1)
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yield previous, objs
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objs = [obj]
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previous = current
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first = False
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if len(fields) > 1:
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objs = nest(objs, 1)
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yield current, objs
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