BUG: unary operators on IntegerArray return shared mask creating inconsistencies when assigning null and non-null values (original) (raw)

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Code Sample, a copy-pastable example

s = pd.Series([1, 2, 3], dtype="Int64") s 0 1 1 2 2 3 dtype: Int64

s2 = -s

s2 0 -1 1 -2 2 -3 dtype: Int64

s[0] = None # assigning None

s 0 1 2 2 3 dtype: Int64

s2 0 # <--- expected -1 1 -2 2 -3 dtype: Int64

s[1] = 10 # assigning a value is ok s 0 1 10 2 3 dtype: Int64

s2 0 1 -2 2 -3 dtype: Int64

s2[2] = None s2 0 1 -2 2 dtype: Int64

s 0 1 10 2 # expected 3 dtype: Int64

s.values._data is s2.values._data False

s.values._mask is s2.values._mask True

Problem description

shared mask leads to an inconsistency when assigning a non-null value compared to assigning a null value

also for __invert__ in BaseMaskedArray so will also affect other nullable arrays

Expected Output

Output of pd.show_versions()

Details

[paste the output of pd.show_versions() here leaving a blank line after the details tag]