Python pandas  use method of merge， return empty DataFrame
#### I use pd.merge to link two excel, but it returns empty dataFrame

``` python
# 
  df1 = pd.read_excel('gz.xlsx')
  df2 = pd.read_excel('dyml.xlsx')
  pd.merge(df1, df2, on = 'name')


```
#### df1 and df2 have the same data in column name,but it can't merge
#### Output of `Empty DataFrame`
