apples-oranges - 8 months ago 36

Python Question

I'm trying to solve a little puzzle, where I need to delete the number 13, and the number after that in a list (its an exercise on CodingBat).

This is my code:

`n = [1, 2, 3, 13, 5, 13]`

for i in n:

if i == 13:

n.remove(i) and n.remove(n.index(i+1))

print n

Desired output:

`[1, 2, 3]`

However, my incorrect output is:

`[1, 2, 3, 5] #the item after 13 (i.e. 5) did not get deleted`

I thought that this

`n.remove(n.index(i+1))`

Answer

This should work:

```
n = [1, 2, 3, 13, 5, 13]
for i in n:
if i == 13:
n.remove(n[n.index(i)+1]) # remove the element after `i` first
n.remove(i)
print n
```

A while loop for the problem:

```
n = [1, 2, 3, 13, 5, 13]
i = 0
while i < len(n):
if n[i] == 13:
n.pop(i)
if i < len(n):
n.pop(i)
else:
i = i + 1
print n
# [1, 2, 3]
```