DOC: Surprising behavior on DataFrame.squeeze() with 0 or 1 col/row

[TomAugspurger]

pd.DataFrame({"A": [1]}).squeeze()  # -> 1
pd.DataFrame({"A": []}).squeeze()  # Noop

The second one is genuinely surprising; I would have expected it to return an empty Series with the name set to A. But it is consisent with numpy (np.array([[], []]).squeeze()) so I've marked is as a doc issue.

[jreback]

hmm, not sure if this is intuitve. I agree in that it should return an empty series. This is prob not tested at all. Maybe change and see if anything affected?

[Winterflower]

@TomAugspurger just testing this issue with pandas version 0.16.2 and I get an empty DataFrame when I do

df = pd.DataFrame({'A':[]})
print df.squeeze()

>>>
Empty DataFrame
Columns: [A]
Index: []

Is this what you meant by Noop?

[TomAugspurger]

Sorry yeah, I should have been clearer. I meant the output was the same as the input (an Empty DataFrame).

[Winterflower]

Ah ok, you meant Noop as in no-operation.

[TomAugspurger]

Yep