On Thu, Feb 20, 2020 at 12:41 PM Steve Jorgensen <ste...@stevej.name> wrote:
> Christopher Barker wrote: > ... > > > Perhaps the OP wanted the internal array size initialized, but not > used. > > Currently the internal array will automatically be reallocated to grow as > > needed. Which could be a performance hit if you know it’s going to grow > > large. > > But frankly, it would be a rare case where this would be noticeable. > > -CHB > > Maybe uncommon, but I don't know about rare. Let's say you want to perform > list-wise computations, making new lists with results of operations on > existing lists (similar to numpy, but maybe trying to do something numpy is > unsuitable for)? You would want to pre-allocate the new array to the size > of the operand arrays. > Strong +1 for an array.zeros() constructor, and/or a lower level array.empty() which doesn't pre-fill values. A use case that came up for me recently is efficiently allocating and filling an object that satisfies the buffer protocol from C/C++ without requiring a NumPy dependency. As far as I can tell, there is no easy way to do this currently.
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