Re: [PATCH] Rewrite feature to render hg-to-git compatible with python2.x and 3.x

Hervé Beraud [off-list ref] writes:

Rewrite features that are no longer supported (or recommended)
in Python 3 in the script so that it can be used with both
Python 2 and 3, namely:

- print is not a statement; use print() function instead.
- dict.has_key(key) is no more; use "key in dict" instead.
- map(lambda ..., collection) is not liked; use list comprehension.

The first two are must haves (iow, without them the code would not
work with Py3), but the last one sounds like a mere preference.  Is
there some authoritative source we can quote (e.g. "PEPx says that
we should prefer X over Y")?

These changes introduce a syntaxe compatible with the both versions of
python.

Python 2 is EOL at the end of 2019, the major part of distros
and systems now come with python 3  is the default version so
these address the situation to render this script compatible with
the latest versions of python.

The explanation looks vaguely familiar.  I would have placed the
background first, and then description of what is done next, perhaps
like:

    Python 2 is EOL at the end of 2019, many distros and systems now
    come with python 3 as their default version.

    Rewrite features that are no longer supported (or recommended)
    in Python 3 in the script so that it can be used with both
    Python 2 and 3, namely:

    - print is not a statement; use print() function instead.
    - dict.has_key(key) is no more; use "key in dict" instead.
    - map(lambda ..., collection) is not liked; use list comprehension.

to make it even easier to read without unnecessary repetition, but
what you wrote is clear enough already.

The patch text looked clearly done.  Nice.