Pandas Series output only shows "inf" values
Hi,
I'm using `Pandas 0.18.1 `(can't upgrade due to dependencies) and I have a `pandas.core.series.Series` with `dtype=float64` and values which I pulled from a CSV file. If I print the series I always get one value while the remaining values are all `inf`.  I access the values using the `history() `method from the `zipline` framework (they didn't know an answer though)

**Series info:**

```
x.shape = (3, )
x.itemsize = 8
```

**Code:**

```
def handle_data(context, data):
    x = data.history(context.i, "open", 3, "1d")
    print(x)
```

**Output:**

```
2017-01-06 00:00:00+00:00           inf
2017-01-09 00:00:00+00:00           inf
2017-01-10 00:00:00+00:00    118.770000
Freq: C, Name: Equity(0 [SIE]), dtype: float64
2017-01-09 00:00:00+00:00           inf
2017-01-10 00:00:00+00:00           inf
2017-01-11 00:00:00+00:00    118.740000
Freq: C, Name: Equity(0 [SIE]), dtype: float64
```

**CSV:**

```
date,open,high,low,close,volume,dividend,split
2017-01-03,115.8,116.33,114.76,116.15,28781900,0,0
2017-01-04,115.85,116.51,115.75,116.02,21118100,0,0
2017-01-05,115.92,116.86,115.81,116.61,22193600,0,0
2017-01-06,116.78,118.16,116.47,117.91,31751900,0,0
2017-01-09,117.95,119.43,117.94,118.99,33561900,0,0
2017-01-10,118.77,119.38,118.3,119.11,24462100,0,0
2017-01-11,118.74,119.93,118.6,119.75,27588600,0,0

```

Thank you!


