See this SO question
The docstring should indicate what is not being copied unnecessarily (Index
es, ndarray
s, etc.)
Comment From: jreback
IIRC I think the copy parameter only matters here is its a trivial merge and you actually do want it copied (kind I like a reindex with the same index)
Comment From: cpcloud
yep here's the explanation:
if the index join is the same as both indexes in the join it will return None
for the indexers and when _JoinUnit.reindex_block
is called copy
will only take effect if the indexer is None
which means what you said: trivial merge
Comment From: cpcloud
still should say something about that....definitely not what i just wrote but something more informative than what's there
Comment From: moaraccounts
take
Comment From: moaraccounts
@jreback @cpcloud I'm having trouble understanding how editing the merge copy parameter documentation resolves this. In the original SO question, OP is using concat, not merge.
It seems like the concat copy parameter needs adjustment, as running through the example from this indicates:
Note It is worth noting that concat() (and therefore append()) makes a full copy of the data, and that constantly reusing this function can create a significant performance hit. If you need to use the operation over several datasets, use a list comprehension.
Maybe I'm missing something?
Comment From: jangorecki
@moaraccounts Maybe this issue is just asking for a different thing than linked SO is about. I subscribed to this issue seeking better "merge" "copy" documentation, not a "concat" copy.
Comment From: TheMellyBee
Can this be closed?
Comment From: Pavanvan
Hi, I'm a new contributor and would like to take this on as my first issue. Could you please assign it to me?
Comment From: jangorecki
Hi, I'm a new contributor and would like to take this on as my first issue. Could you please assign it to me?
Do you know what needs to be done here exactly?