pivot_table returns a Series instead of a DataFrame depending upon the datatype of the values parameter
My python code looks like

```
df = pandas.read_csv("a.csv")
print df
table = pandas.pivot_table(df, values=['Sales1'] ,rows='State' , aggfunc=np.sum)
print type(table)
table = pandas.pivot_table(df, values='Sales1' ,rows='State' , aggfunc=np.sum)
print type(table)

Contents of a.csv
City,Sales1
Mumbai,1

The Output
City  Sales1
0  Mumbai       1
<class 'pandas.core.frame.DataFrame'>
<class 'pandas.core.series.Series'>
```

My question is why would a change in the datatype of the  values parameter return a DataFrame instead of a Series. After all we use an array only if we have to pass multiple values.

Thank You.

Vijay Mukhi
