How to print multiple lists together?

Question

Is there a way to print out 2 lists together, for one I can do for

for g in grades:
    print(g)

Which results in: 83, 25, 90 etc.. I have a second list called 'cc'. Both lists have the same number of items in the proper order. I'm trying to print them as

print(cc[0])
print(g[0])

And so on for all the items in the list.

I've already tried

for g in grades:
    for x in cc:
        print(x)
        print(g)

Which as expected prints out many more times than once for each. Is there a way to properly do this? I think I'm writing this clear enough.

Reblochon Masque · Accepted Answer · 2017-10-19T00:09:43.287

3

Since the two lists have the same length, you can use zip.

zip creates a tuple of the successive items in each sequence. g, x "unpacks" this tuple; that is assign the respective values to g and x.

for x, g in zip(cc, grades):
    print(x, g, end='\n')

edited Oct 19 '17 at 00:09

answered Oct 19 '17 at 00:07

Reblochon Masque

35,405
10
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Yes, good point, thanks. – Reblochon Masque Oct 19 '17 at 00:11
You have enough reputation to find and VTC these excessively basic questions as duplicates, do you still feel it'd be better to answer them? – cs95 Oct 19 '17 at 00:19

Andrzej S. · Answer 2 · 2017-10-19T03:33:13.777

0

You can use index function:

list1 = ['a','b','c']
list2 = [0,1,2]

for i in list1:
    print(i)
    print(list2[list1.index(i)])

Updated (thanks for @juanpa.arrivillaga):

But it's a bad solution because it has quadratic-time algorithm. It's better to use enumerate:

for index, item in enumerate(list1):
    print(item)
    print(list2[index])

edited Oct 19 '17 at 03:33

answered Oct 19 '17 at 00:10

Andrzej S.

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19

You now have a quadratic-time algorithm. Don't use `list1.index`, rather, *enumerate* list1, so `for i, e in enumerate(list1):` – juanpa.arrivillaga Oct 19 '17 at 00:11
@juanpa.arrivillaga thanks! – Andrzej S. Oct 19 '17 at 00:16
Just remember, `my_list.count` and `my_list.index` are O(n). They are very fast and efficient if you do them outside a loop, but inside a loop, they can kill the runtime of your algorithm! – juanpa.arrivillaga Oct 19 '17 at 00:20

How to print multiple lists together?

2 Answers2