Printing mapped items in reverse order

Question

Given a map of simple integers:

this_map = map(int, input().split())
2 4 1 3 5

How do I print this_map in reverse order? I can print each item with a simple for loop but printing the thing in reverse format requires indexing and this is not possible through standard procedure.

for item in this_map[::-1]:
    print(item)

TypeError: 'map' object is not subscriptable

A similar post on using enumerate() exists but how do I use it here to add indexes?

Note: I'm using Python 3.6

Netwave · Answer 1 · 2018-06-26T15:10:56.673

2

Just use reversed:

this_map = map(int, reversed("2 4 1 3 5".split()))
for item in this_map:
    print(item)

edited Jun 26 '18 at 15:10

answered Jun 26 '18 at 15:07

Netwave

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@Shiv_90, cannot use with map, so you would have to work over the input split. – Netwave Jun 26 '18 at 15:11
Thanks for the highlight. `reversed()` works as you just described above. Gordon's answer worked. – shiv_90 Jun 26 '18 at 15:17

score 2 · Accepted Answer · answered Jun 26 '18 at 15:11

2

Your example didn't work because map() behaves differently in Python 2 vs Python 3. In Python 2 it returns a list, but in Python 3 it returns a special map object.

You can convert it to a list by calling list() on it:

this_map = list(this_map)

answered Jun 26 '18 at 15:11

John Gordon

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This is the only way for a map. – shiv_90 Jun 26 '18 at 15:22

score 0 · Answer 3 · answered Jun 26 '18 at 15:07

0

Have you tried this:

for i in reversed(this_map):
    print(i)

answered Jun 26 '18 at 15:07

Taohidul Islam

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score 0 · Answer 4 · answered Jun 26 '18 at 15:16

0

Just convert the map into a list first

this_map = list(map(int, input().split()))
for item in this_map[::-1]:
    print(item)

answered Jun 26 '18 at 15:16

Sudarshan

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Printing mapped items in reverse order

4 Answers4