py3 some care for .items

[fchapoton]

as another step to py3, issue found using a python3 build

CC: @tscrim @jdemeyer @jhpalmieri @a-andre @kiwifb

Component: python3

Author: Frédéric Chapoton

Branch/Commit: df80274

Reviewer: Jeroen Demeyer

Issue created by migration from https://trac.sagemath.org/ticket/23824

[fchapoton]

New commits:

04f2059

py3 fixing calls of .items()[...]

[fchapoton]

Branch: u/chapoton/23824

[fchapoton]

Commit: 04f2059

[jdemeyer]

comment:2

I think it is better style to write

            (e, c), = d.items()

instead of

            e, c = next(iter(d.items()))

to get the unique element of some iterator.

[fchapoton]

comment:3

but d.items() is not an iterator in python3

[jdemeyer]

comment:4

Replying to @fchapoton:

but d.items() is not an iterator in python3

I meant iterable and that should be case for Python 2 and Python 3.

And for list(sequence)[:n], I would suggest instead islice(sequence, n) (with from itertools import islice)

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

df80274

trac 23824 better syntax

[sagetrac-git]

Changed commit from 04f2059 to df80274

[fchapoton]

comment:6

thanks, done

[jdemeyer]

Reviewer: Jeroen Demeyer

[jdemeyer]

comment:7

Great! You can set positive review if it passes tests.

[fchapoton]

comment:8

bot is green enough

[vbraun]

Changed branch from u/chapoton/23824 to df80274