Aji Peatama - 2 months ago 3x
Python Question

# Python operation data List in loop

I want to solve my programming problem, the problem goes like so:

``````input: 3 #if i input as first input example 3, output is [1, 2, 3]
[1, 2, 3]
input: 2  #2nd input example 2 output is [1, 2] + [1, 2, 3] = [2, 4, 6]
[2, 4, 3]
input: 6 #3rd input [2, 4, 6] + [1, 2, 3, 4, 5, 6] = [3, 6, 6, 4, 5, 6]
[3, 6, 6, 4, 5, 6]
``````

My code:

``````while True:
a = input('Input : ')
n = range (1,a+1,1)

print n
``````

Outputs:

`````` Input : 3
[1, 2, 3]
Input : 2
[1, 2]
Input : 6
[1, 2, 3, 4, 5, 6]
``````

How can I solve this problem?

but i can not use external code

Then you can write some code that does exactly what `izip_longest` does with the zero padding when the new entry is lengthier than the previous result.

The sums are performed in a list comprehension where the values and indices from the input list are gotten by applying `enumerate` on the entry in the comprehension. Values from the accumulated list are indexed and added to new values at the same index:

``````tot = []
while True:
a = input('Input : ')
n = range (1,a+1,1)
x, y = len(tot), len(n)
if y > x:
tot[x:y] = [0]*(y-x) # pad the tot list with zeros
tot[:y] = [tot[i]+v for i, v in enumerate(n)]
print tot
``````

Output:

``````Input : 3
[1, 2, 3]
Input : 2
[2, 4, 3]
Input : 6
[3, 6, 6, 4, 5, 6]
Input : 1
[4, 6, 6, 4, 5, 6]
Input : 0
[4, 6, 6, 4, 5, 6]
``````
Source (Stackoverflow)