Split sentences in pandas into sentence number and words

I have a pandas dataframe like this:

Text            start    end    entity     value
I love apple      7       11    fruit      apple
I ate potato      6       11    vegetable  potato

I have tried to use a for loop It's running slow and I don't think this is what we should do with pandas.

I want to create another pandas dataframe base on this like:

Sentence#         Word        Tag
  1                I         Object 
  1               love       Object
  1               apple      fruit
  2                I         Object
  2               ate        Object
  2               potato     vegetable

Split the text column into words and sentence numbers. Other than the entity word, the other words will be tagged as Object.

Use split, stack and map:

u = df.Text.str.split(expand=True).stack()

pd.DataFrame({
    'Sentence': u.index.get_level_values(0) + 1, 
    'Word': u.values, 
    'Entity': u.map(dict(zip(df.value, df.entity))).fillna('Object').values
})

   Sentence    Word     Entity
0         1       I     Object
1         1    love     Object
2         1   apple      fruit
3         2       I     Object
4         2     ate     Object
5         2  potato  vegetable

Side note: If running v0.24 or later, please use .to_numpy() instead of .values.