'df_1' is not defined

I have successfully loaded the file but an error has appeared
```
NameError                                 Traceback (most recent call last)
<ipython-input-1-e0e4dd6ce4e3> in <module>()
      1 # do the grouping
      2 
----> 3 df_1_list = df_1.Keyword.tolist()  # create list from df
      4 model = PolyFuzz("TF-IDF")
      5 try:

NameError: name 'df_1' is not defined
```