How to iterate through a list in Python without using a "for" loop? [closed]

Question

I want to print all the elements in the range from 2 to 8 then use for loop:

E.g:

for i in range(2,8):
    print(i)

What is the best method to iterate without using a for, or while loop, which reduces the time complexity?

Answer 1

How about using recursion?

def iterate(lst, start, end):
  if start < 0 or end >= len(lst) or start > end:
    return
  print(lst[start])
  iterate(lst, start + 1, end)

Call it like this:

iterate([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 2, 8)

Answer 2

Let's take this sample list:

>>> mylist
['zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine']

Now, let's print elements 2 through 8 without looping:

>>> ' '.join(mylist[2:9])
'two three four five six seven eight'

Here, 2:9 tells python to uses indices starting with 2 and continuing up to but not including 9.

Answer 3

By slicing the list

>>> l = [1,2,3,4,5,6,7,8,9,10]
>>> print(l[1:8])
[2, 3, 4, 5, 6, 7, 8] # output in console

To get the summation of the values in l[1:8] use sum

>>> sum(l[1:8])
35 # output

EDIT because of @pzp:

If you want to print all the elements between index 2 and index 8 both inclusive,just replace print(l[1:8]) in the code above with print(l[2:9]).

Answer 4

simple solution using list comprehension

list1 = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
sum1 = sum([i for i in list1 if i > 2 and i < 9])