Input list: [1, 2, 3, 4, 5]
Output: [5, 4, 3, 2, 1]
I know how to do it with for loop, but my assignment is to do it with while loop; which I have no idea to do. Here is the code I have so far:
def while_version(items):
a = 0
b = len(items)
r_list = []
while (a!=b):
items[a:a] = r_list[(-a)-1]
a+=1
return items
I would say to make the while loop act like a for loop.
firstList = [1,2,3]
secondList=[]
counter = len(firstList)-1
while counter >= 0:
secondList.append(firstList[counter])
counter -= 1
The simplest way would be:
def while_version(items):
new_list = []
while items: # i.e. until it's an empty list
new_list.append(items.pop(-1))
return new_list
This will reverse the list:
>>> l1 = [1, 2, 3]
>>> l2 = while_version(l)
>>> l2
[3, 2, 1]
Note, however, that it also empties the original list:
>>> l1
[]
To avoid this, call e.g. l2 = while_version(l1[:]).
The trivial answer
Given
a = [1, 2, 3, 4, 5]
then
a[::-1]
returns
[5, 4, 3, 2, 1]
In your code:
Hope this helps
return itemsis indented, so it will happen the first time through the loop.