how to create a column of ascending numbers by a certain value?

Question

How do I make a list or column in pandas which number in this column increase itself by step of 1 and when it hits an certain number (let's say 5) it return to 1 and repeat this process? My scripts like below and it won't work as expected:

i = 0
lista = []
for i in range(50):
        i += 1
        if i == 5:
            continue
        lista.append(i)

print(i)
# what I wanted from this code is like :
1
2
3
4
5
.
.
.
# repeat printing 1-5 for 10 times

While vectorized solutions are preferable (see answer below), you can achieve the same task with the following code which fixes your one: `for i in range(50): lista.append((i % 5) + 1)` — Roberto Trani, Aug 05 '20 at 08:01
My comment was just to let him know how to fix his starting code :) — Roberto Trani, Aug 05 '20 at 08:36

score 2 · Answer 1 · answered Aug 05 '20 at 07:56

First using loops in pandas is antipattern, mainly if exist vectorized solutions, here numpy.tile:

df = pd.DataFrame({'col': np.tile(np.arange(1, 6), 10)})
print (df.head(12))
    col
0     1
1     2
2     3
3     4
4     5
5     1
6     2
7     3
8     4
9     5
10    1
11    2

score 0 · Accepted Answer · answered Aug 05 '20 at 08:05

0

In the simplest way that occurs to me:

lista = []
for i in range(50):
    lista.append(i%5+1)
print(lista)

This could also be written as a list comprehension, which is only one line of code and way cooler ;)

lista = [ i%5+1 for i in range(50) ]

answered Aug 05 '20 at 08:05

AllAboutMike

121
7

how to create a column of ascending numbers by a certain value?

2 Answers2