Modify parents dict() argument in child definition

Asked Oct 29 '18 at 15:04

Active Oct 29 '18 at 15:04

Viewed 16 times

Say I have a class A:

class A:
    list_attribute = ['foo', 'bar']
    dict_attribute = {'foo': 'bar'}

A is extended by B, and in B I want to add elements to list_attribute in the declaration of the class, it is pretty easy

class B(A):
    list_attribute = A.list_attribute + ['foobar', 'barfoo']

My question is, how can I add elements to the dict_attribute the same way I did for the list_attribute (in the attribute definition, and not in the __init__), since dicts don't support the + operator ?

Thanks in advance and have a great day!

asked Oct 29 '18 at 15:04

Fawak

`dict_attribute.update(new_dict)` – Vineeth Sai Oct 29 '18 at 15:06
dict_attribute.update( {'foobar': 'barfoo' }) – Serge Oct 29 '18 at 15:06
2

@VineethSai **No!** That will update `A.dict_attribute`. You have to make a copy for `B`. – Aran-Fey Oct 29 '18 at 15:07
or dict_attribute['foobar'] = 'barfoo'... – Serge Oct 29 '18 at 15:07
@Serge Also **no**! – Aran-Fey Oct 29 '18 at 15:07
@Aran-Fey Oh yes!. Thank you for the correction. – Vineeth Sai Oct 29 '18 at 15:08
ok ... B.dict_attribute = {'foobar': 'barfoo' }.update(A.dict_attribute) – Serge Oct 29 '18 at 15:08
@Serge the update method doesn't return the dict, so it can't be used in the attribute definition – Fawak Oct 29 '18 at 15:09
1

for one liner dict(d2.items() + d1.items()) – Serge Oct 29 '18 at 15:12
Although I used the solution given in the question linked by @Aran-Fey, this works too indeed, thanks :) – Fawak Oct 29 '18 at 15:14

Modify parents dict() argument in child definition

0 Answers0