Remove elements from a ListAttribute using a list of indexes #754
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dotpmrcunha
requested review from
jpinner-lyft and
garrettheel
and removed request for
jpinner-lyft
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This looks good overall! Would you mind adding some docs to |
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Hi, added the document and the example. Thanks |
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Thanks @dotpmrcunha. I fixed the travis build reporting and it now shows a type error. I'd suggest changing the type signature of |
pynamodb/attributes.py
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| @@ -961,6 +962,13 @@ def __init__(self, hash_key=False, range_key=False, null=None, default=None, att | |||
| raise ValueError("'of' must be subclass of MapAttribute") | |||
| self.element_type = of | |||
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| def remove(self, indexes=None): | |||
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Apologies for not suggesting earlier, but having thought about this a bit it's probably better to have a separate remove_indexes function on ListAttribute rather than overloading the existing remove. What do you think?
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Well... while adding the indexes attribute, I was also thinking in same, separate the methods. I will do that then, it makes more sense.
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And also, instead of using:
class ListAttribute:
def remove_indexes(self, indexes):
....
Thread.notes.remove_indexes([1,2,...])
I add like this:
class ListAttribute:
def remove_indexes(self, *indexes):
....
Thread.notes.remove_indexes(1, 2, ...)
What do you think?
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Makes sense to use varargs 👍
docs/updates.rst
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| @@ -44,4 +44,5 @@ Any value provided will be serialized using the serializer defined for that attr | |||
| `attr_or_value_1` \- `attr_or_value_2`, `attr_or_value_1` \- `attr_or_value_2`, 5 - Thread.views | |||
| "list_append( `attr` , `value` )", append( `value` ), Thread.notes.append(['my last note']) | |||
| "list_append( `value` , `attr` )", prepend( `value` ), Thread.notes.prepend(['my first note']) | |||
| "REMOVE list[index1], list[index1]", "remove_indexes(`index1`, `index2`)", "Thread.notes.remove_indexes(0, 1)" | |||
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| "REMOVE list[index1], list[index1]", "remove_indexes(`index1`, `index2`)", "Thread.notes.remove_indexes(0, 1)" | |
| "REMOVE list[index1], list[index2]", "remove_indexes(`index1`, `index2`)", "Thread.notes.remove_indexes(0, 1)" |
This reverts commit a5f2369.
Based on the AWS documents https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.UpdateExpressions.html#Expressions.UpdateExpressions.REMOVE
It is possible to delete items from a list inside a ListAttribute using:
--update-expression "REMOVE RelatedItems[1], RelatedItems[2]"This way I extended the remove in the ListAttribute and added the indexes argument, if there is a valid integer List it will remove the selected elements.
Usage:
list_attribute.remove(indexes=[0, 10])