pydata/pandas — pull request #8075 by jreback (2014-08-20 00:13:51+00:00)
Title: ENH: add support dtype='category' in Series constructor

xref #8074
```
In [1]: Series([1,1,2,2,3,4,5],dtype='category')
Out[1]:
0 1
1 1
2 2
3 2
4 3
5 4
6 5
dtype: category
Levels (5, int64): [1 < 2 < 3 < 4 < 5]
```