groupbyattr 1.0.1
Group items in a sequence by the value of a shared attribute.
group_by_attr(attr, items)
Installation:
$ pip install group-by-attr
Example
Let’s say you want to group some “Struct” instances together.
>>> from pprint import pprint
>>> from collections import namedtuple
>>> Struct = namedtuple('Struct', ('x', 'y', 'z'))
>>> a, b, c = (
... Struct(x=1, y=1, z=1),
... Struct(x=1, y=2, z=2),
... Struct(x=1, y=1, z=3))
If we were to group these instances by the ‘x’ attribute, we should
expect a single group containing all three items:
>>> pprint(group_by_attr(attr='x', items=(a, b, c)))
{1: (Struct(x=1, y=1, z=1),
Struct(x=1, y=2, z=2),
Struct(x=1, y=1, z=3))}
If, instead, we were to group by ‘y’, we should expect a different
grouping:
>>> pprint(group_by_attr(attr='y', items=(a, b, c)))
{1: (Struct(x=1, y=1, z=1),
Struct(x=1, y=1, z=3)),
2: (Struct(x=1, y=2, z=2),)}
Finally, grouping by ‘z’ will result in three separate groups:
>>> pprint(group_by_attr(attr='z', items=(a, b, c)))
{1: (Struct(x=1, y=1, z=1),),
2: (Struct(x=1, y=2, z=2),),
3: (Struct(x=1, y=1, z=3),)}
This function can also use an alternate getattr, as long as it implements
the same interface (taking an item and an attribute name as arguments).
For example, you could group dictionaries:
>>> pprint(group_by_attr(
... attr='x',
... items=(
... {'x': 1, 'y': 'a'},
... {'x': 2, 'y': 'b'},
... {'x': 1, 'y': 'c'}),
... getattr_fn=dict.__getitem__))
{1: ({'x': 1, 'y': 'a'},
{'x': 1, 'y': 'c'}),
2: ({'x': 2, 'y': 'b'},)}
For personal and professional use. You cannot resell or redistribute these repositories in their original state.
There are no reviews.