Implement packing/unpacking in an object
A better option for unpacking Python 3.7+ dataclasses is as follows:
from dataclasses import astuple, dataclass
@dataclass
class Item:
name: str
age: int
gender: str
def __iter__(self):
return iter(astuple(self))
a, b, c = Item("Henry", 90, "male")
You can unpack any Iterable
. This means you need to implement the __iter__
method, and return an iterator. In your case, this could simply be:
def __iter__(self):
return iter((self.name, self.age, self.gender))
Alternatively you could make your class an Iterator
, then __iter__
would return self
and you'd need to implement __next__
; this is more work, and probably not worth the effort.
For more information see What exactly are Python's iterator, iterable, and iteration protocols?
Per the question I linked above, you could also implement an iterable with __getitem__
:
def __getitem__(self, index):
return (self.name, self.age, self.gender)[index]
Another option would be a named tuple
Item = collections.namedtuple('Item', ['name', 'age', 'gender'])
So this works out of the box:
a, b, c = Item("Henry", 90, "male")
If you're on Python 3.7+, you could also take advantage of dataclasses which are more powerful. But you would need to explicitly call astuple
:
@dataclasses.dataclass
class Item(object):
name: str
age: int
gender: str
a, b, c = dataclasses.astuple(Item("Henry", 90, "male"))