Select only the bottom continuous rows where specific value is present Pandas

Question

I have the below data frame lst = [['A',1],['B',0],['C',1],['D',0],['E',1],['F',1],['G',1]] df = pd.DataFrame(lst,columns = ['name','val']) Looks like this name val 0 A 1 1 B 0 2 C 1 3 D 0 4 E 1 5 F 1 6 G 1 I am trying to get rows where val is 1 but they should be bottom continuous rows. Desired output name val 4 E 1 5 F 1 6 G 1 I am doing, which will give all val with 1. df[df.val == 1] Select the correct answer from above options

Answer 1

You can use cumsum to get the last block: # blocks separated by `0` s = df.val.ne(1).cumsum() # last blocks and only value 1 df[s.eq(s.max()) & df['val'].eq(1)] Output: name val 4 E 1 5 F 1 6 G 1 Learn Python for Data Science Course to improve your technical knowledge.