[FIXED] How to extract data from a list of tuples which length could be variable

Issue

I have a list which contains multiple tuples (the length of items is variable) and I want to extract some specific data located at the same rank inside the tuples.

Let me show you an example. Let's work on this list of 3 tuples:

x = [
    ('a1', 'b2', 'c3', 'd4'), 
    ('e5', 'f6', 'g7', 'h8'), 
    ('i9', 'j10', 'k11', 'l12')
]

I want to retrieve the fourth items of each tuples. I use the length of the list within a While loop:

y = len(x)
while y > 0:
    print(x[0][3])
    y = y - 1

The result I get is:

d4
d4
d4

But I want the following result:

d4
h8
l12

Is there a way to replace the [0] by the y variable inside this section print(x[0][3]) to get the result I want?

Solution

It would be more natural to use a for loop for this:

for item in x:
    print(item[3])

The reason your code didn't work was because you had hard-coded it to always get the first tuple in your list i.e. in print(x[0][3]) the 0 in x[0] needed to be a variable that iterates through your list. This would be easier if you count up instead of down i.e.

counter = 0
while counter < len(x):
    print(x[counter][3])
    counter += 1

but it really doesn't make sense to use while for this when for exists.

Answered By - Dan