String.split 停止在最后一个元素 python

Question

I am using str.split to split the data I have after a regex from one column into two columns.

The data is:

DATA_SET 
1  98
2 176
3 277 
.... 
16 790

DATA_SET
1   8
2  37
3 378
.... 
16 899

I have a piece of code that works with individual data sets to split the column into two columns.

f = pd.read_table('my_file.txt')

f[['D1 ', 'D2']] = f['DATA_SET'].str.split(expand=True)

How can I specify to the code that when it reaches the item “16” it needs to stop the split operation? And do it again after it encounters the next “DATA_SET”

Answer 1

Apply the split to the rows you are interested, ie where index is less equal 16

f[['D1 ', 'D2']] = f.loc[:16, 'DATA_SET'].\
    str.split(expand=True)