TST/CoW: expand test for chained inplace methods #56402
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| getattr(df["a"], func)(*args, inplace=True) | ||
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| def test_methods_iloc_getitem_item_cache_fillna( |
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I added a second version of this test with all hardcoded fillna() calls, so this isn't using *args, and we also have one version without this (in theory we could do this for each of the methods, but given the code is reused in each of the methods, I think just one is also fine)
| # TODO(CoW-warn) because of the usage of *args, this doesn't warn on Py3.11+ | ||
| if using_copy_on_write: | ||
| with tm.raises_chained_assignment_error(not PY311): | ||
| getattr(df["a"], func)(*args, inplace=True) |
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I updated the first test to also use getattr(..)(*args) for this part of the test, which means we are for now asserting this incorrectly doesn't raise a warning for 3.11+ because of the different ref count when using *args
| # TODO(CoW-warn) ideally also warns on the default mode, but the ser' _cacher | ||
| # messes up the refcount | ||
| with tm.assert_cow_warning(warn_copy_on_write, match="A value"): | ||
| df["a"].fillna(1, inplace=True) |
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I added one more test case to both tests where we populate the item cache but also keep that series object alive. In this case, because that increases the ref count in the non-CoW or non-warn mode (the df['a'] is cached), this doesn't give a warning.
Not sure we can do something about this, though, given the fact we cache the getitem return value and reuse that.
But at least, the good part, is that it does correctly warn on the warning mode. So for users that do the migration in steps, they should see the warning then.
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Thanks @jorisvandenbossche |
* TST/CoW: expand test for chained inplace methods * fix test for older python --------- Co-authored-by: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Another follow-up on #56400