Daiyue Weng writes:
> Hi, I am trying to update a list of dictionaries using another list of
> dictionaries correspondingly. In that, for example,
>
> # the list of dicts that need to be updated
> dicts_1 = [{'dict_1': '1'}, {'dict_2': '2'}, {'dict_3': '3'}]
>
> # dict used to update dicts_1
> update_dicts = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> so that after updating,
>
> dicts_1 = [{'dict_1': '1_1'}, {'dict_2': '1_2'}, {'dict_3': '1_3'}]
>
> what's the best way to the updates?
>
> This is actually coming from when I tried to create a list of entities
> (dictionaries), then updating the entities using another list
> dictionaries using google.cloud.datastore.
>
> entities = [Entity(self.client.key(kind, entity_id)) for entity_id in
> entity_ids]
>
> # update entities using update_dicts
> for j in range(len(entities)):
> for i in range(len(update_dicts)):
> if j == i:
> entities[j].update(update_dicts[i])
[I restored the indentation.]
> I am wondering is there a brief way to do this.
A straightforward algorithmic improvement:
for j in range(len(entities)):
entities[j].update(update_dicts[j])
The real thing:
for e, u in zip(entities, update_dicts):
e.update(u)
A thing between those:
for j, e in enumerate(entities):
e.update(update_dicts[j])
(By symmetry, you could enumerate update_dicts instead.)
It pays to learn zip and enumerate.
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