How to print the element in a list with index?

Question

I'm trying to print the element with the index of every element in the list

But my implement prints every element with index 0 and every element with index 1 until the last index

can anyone fix it, I'm stuck here?

if __name__=="__main__":

    r = [6, 5, 3, 3]
    diff = [[(i,j)for i in r]for j in range(5)]
    print(diff)

Actual output:

[[(6, 0), (5, 0), (3, 0), (3, 0)], [(6, 1), (5, 1), (3, 1), (3, 1)], [(6, 2), (5, 2), (3, 2), (3, 2)], [(6, 3), (5, 3), (3, 3), (3, 3)], [(6, 4), (5, 4), (3, 4), (3, 4)]]

Desired output:

[(6, 0),(5, 1),(3, 2),(3, 3)]

What should the output be? – Matt Ball Apr 03 '16 at 20:52 — Matt Ball, Apr 03 '16 at 20:52
http://stackoverflow.com/q/522563/139010 – Matt Ball Apr 03 '16 at 20:55 — Matt Ball, Apr 03 '16 at 20:55

score 2 · Accepted Answer · answered Apr 03 '16 at 20:54

2

Try enumerate:

diff = [(i, j) for j, i in enumerate(r)]

A less preferrable way would be to use zip:

diff = list(zip(r, range(len(r))))

answered Apr 03 '16 at 20:54

VHarisop

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dnit13 · Answer 2 · 2016-04-03T21:11:20.530

1

You are looking for enumerate , which gives you the element with index like this:

>>> r = [6, 5, 3, 3]
>>> output = [(val, indx) for indx, val in enumerate(r)]
>>> output
[(6, 0), (5, 1), (3, 2), (3, 3)]

a simple way to understand enumerate:

diff = [(r[i], i) for i in range(len(r))]

edited Apr 03 '16 at 21:11

answered Apr 03 '16 at 20:55

dnit13

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score 1 · Answer 3 · answered Apr 03 '16 at 20:56

1

I think you're asking for the functionality provided by enumerate() (getting both the value and index of an iterable)

r = [6, 5, 3, 3]
print([(val, i) for i, val in enumerate(r)])

answered Apr 03 '16 at 20:56

jDo

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How to print the element in a list with index?

3 Answers3