How to combine multiple rows of strings into one using pandas?

Question

I have a DataFrame with multiple rows. Is there any way in which they can be combined to form one string?

For example:

     words
0    I, will, hereby
1         


        

Answer 1

For anyone want to know how to combine multiple rows of strings in dataframe,
I provide a method that can concatenate strings within a 'window-like' range of near rows as follows:

# add columns based on 'windows-like' rows
df['windows_key_list'] = pd.Series(df['key'].str.cat([df.groupby(['bycol']).shift(-i)['key'] for i in range(1, windows_size)], sep = ' ')

Note: This can't be reached by groupby, because we don't mean the same id of rows, just near rows.