How to print this series

Question

1
12
123
1234

Answer 1

For example by using a loop and the range() function.

What have you tried so far? Please link your own code attempt.

Answer 2

x = int(input()) #4
s = ""
for i in range(x):
s+=str(i+1)
print(s)

Answer 3

Use looping statement to this series

Answer 4

I'm new in python how can i improve my seft