array.delete_at(offset [,end_offset]) → array
Remove one or more elements from an array at a given index. Returns the modified array. (Note: delete_at
operates on arrays, not documents; to delete documents, see the delete command.)
If only offset
is specified, delete_at
removes the element at that index. If both offset
and end_offset
are specified, delete_at
removes the range of elements between offset
and end_offset
, inclusive of offset
but not inclusive of end_offset
.
If end_offset
is specified, it must not be less than offset
. Both offset
and end_offset
must be within the array’s bounds (i.e., if the array has 10 elements, an offset
or end_offset
of 10 or higher is invalid).
By using a negative offset
you can delete from the end of the array. -1
is the last element in the array, -2
is the second-to-last element, and so on. You may specify a negative end_offset
, although just as with a positive value, this will not be inclusive. The range (2,-1)
specifies the third element through the next-to-last element.
Example: Delete the second element of an array.
> r.expr(['a','b','c','d','e','f']).delete_at(1).run(conn) ['a', 'c', 'd', 'e', 'f']
Example: Delete the second and third elements of an array.
> r.expr(['a','b','c','d','e','f']).delete_at(1,3).run(conn) ['a', 'd', 'e', 'f']
Example: Delete the next-to-last element of an array.
> r.expr(['a','b','c','d','e','f']).delete_at(-2).run(conn) ['a', 'b', 'c', 'd', 'f']
Example: Delete a comment on a post.
Given a post document such as:
{ id: '4cf47834-b6f9-438f-9dec-74087e84eb63', title: 'Post title', author: 'Bob', comments: [ { author: 'Agatha', text: 'Comment 1' }, { author: 'Fred', text: 'Comment 2' } ] }
The second comment can be deleted by using update
and delete_at
together.
r.table('posts').get('4cf47834-b6f9-438f-9dec-74087e84eb63').update( lambda post: { 'comments': post['comments'].delete_at(1) } ).run(conn)
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