Case where xs(copy=False) does not return view. #2117
Description
from stackoverflow
In [25]: cpaste
Pasting code; enter '--' alone on the line to stop or use Ctrl-D.
:>>> index = pd.MultiIndex.from_arrays([['a','a', 'b', 'b'], [1,2,1,2]],
:... names=['first', 'second'])
:>>> data = pd.DataFrame(np.random.rand(len(index)), index=index, columns=['A'])
:>>> print data
:--
A
first second
a 1 0.026915
2 0.777457
b 1 0.445726
2 0.243053
In [26]: selected = data.xs(2, level='second', copy=False)
In [27]: selected
Out[27]:
A
first
a 0.777457
b 0.243053
In [28]: selected['A'][0] = 100
In [29]: selected
Out[29]:
A
first
a 100.000000
b 0.243053
In [30]: data
Out[30]:
A
first second
a 1 0.026915
2 0.777457
b 1 0.445726
2 0.243053