ValueError("Cannot describe a DataFrame without columns") ValueError: Cannot describe a DataFrame without columns
This is my TestWorkbook.xlsx in same location as my python script:
```
Data    Time    Variable    Value
08/01/17    06:00:30     Occupancy.1m.15s.mean          497.714
08/01/17    06:00:30     QueueTime.1m.15s.mean      698.999
08/01/17    06:00:30     QueueStatus.1m.15s.mean    42.8639
08/01/17    06:00:30     QueueTime.1m.15s.mean      113.139
```

```python
import pandas as pd
import numpy as np
import glob

all_data = pd.DataFrame()

res = glob.glob("*.xlsx")

for f in glob.glob("TestWorkbook.xlsx"):
    df = pd.read_excel(f, sheetname='Sheet1')
    all_data = all_data.append(df, ignore_index=True)

all_data.describe()

```
 
Not sure why it is returning error

    raise ValueError("Cannot describe a DataFrame without columns")
    ValueError: Cannot describe a DataFrame without columns
 
