Create a pandas column counter that successively counts 4 lines and 6 lines

Question

I have a pandas dataframe with multiple columns and I want to create a counter that successively counts 4 rows and 6 rows. I would like it to look like the dataframe below:

index	counter
0	1
1	1
2	1
3	1
4	2
5	2
6	2
7	2
8	2
9	2
10	3
11	3
12	3
13	3

As you can see, the first 4 values in counter column is 1, then next 6 values are 2, then again next 4 values are 3.

Answer 1

Your question is a bit clear after edit, you can create an empty list and a counter variable, then iterate on the range of number of rows incrementing it by 10 i.e. (4+6), then at each iteration, create the required lists of length 4 and 6 with counter and counter+1, add it to the resulting list. Finally take the slice from result list first df.shape[0] values (because it may have few more values than df.shape[0]), and assign it to the new column df['counter'].

result = []
counter = 1
for i in range(0, df.shape[0], 10):
    result += [counter]*4
    counter += 1
    result += [counter]*6
    counter += 1

df['counter'] = result[:df.shape[0]]
    
# result [1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4]

OUTPUT:

    index  counter
0       0        1
1       1        1
2       2        1
3       3        1
4       4        2
5       5        2
6       6        2
7       7        2
8       8        2
9       9        2
10     10        3
11     11        3
12     12        3
13     13        3