DOC: minor doc fix for Series.append; indices can overlap

[jakevdp]

Old docstring seemed to be incorrect; overlapping indices are supported e.g.

>>> import pandas as pd
>>> x = pd.Series(['A', 'B', 'C'])
>>> y = pd.Series(['D', 'E', 'F'])
>>> x.append(y)
0    A
1    B
2    C
0    D
1    E
2    F
dtype: object

[mortada]

This would raise if verify_integrity=True though, seems like what that was meant for.

In [6]: x.append(y, verify_integrity=True)
ValueError: Indexes have overlapping values: [0, 1, 2]

Perhaps a good idea to do this?

 The indexes must not overlap if verify_integrity is True

[jakevdp]

The documentation of verify_integrity already says this pretty clearly. I'm not sure the information needs to be repeated in the general description. For what it's worth, DataFrame.append and pd.concat both have the same behavior, and don't mention anything about duplicate indices in the general description.

[jorisvandenbossche]

I think this looks good!

[mortada]

@jakevdp ah I see, yeah that makes sense

[jorisvandenbossche]

@jakevdp Thanks!