Python 3 preparation: Change syntax of octal integer literals

[wluebbe]

The deprecated syntax is not accepted by Python 3.

Changes according to lib2to3/fixes/fix_numliterals.py:

0755 into 0o755

This ticket is tracked as a dependency of meta-ticket ticket:16052.

[wluebbe]

search result for integer literals with suffix "L" (type long)

[wluebbe]

The changes for the new octal literal format should be complete: 2 modules were fixed by the 2to3 tool and another case was manually fixed in a doc-test.

2to3 has found nothing for the long integer literal (suffix "L").
13 modules were found with regexp search (r"\s (0\d+) [\s)]"). The result file is attached.

• 6 pyx modules from sage/rings/padics contain code like (1L << (sizeof(long) * 8 - 2)) - 1. I do not whether these should be changed.
• 4 modules had doc-test with stuff like 4561L # 32-bit. Perhaps these test can be made more tolerant.
• The module sage/interfaces/r.py had strings like
  "rel_re_integer.sub(a._subs_integer, ' 1L 2L')". Maybe this could / should be changed.
• 2 modules in sage/combinat had the text "ValueError?: R10L is not a correct map". Nothing to change.

---

New commits:

​a17cb52

changed to new octal literal format (in 3 modules)

[wluebbe]

I did

git merge u/chapoton/15991 u/wluebbe/ticket/15986 u/wluebbe/ticket/15987

on top of u/wluebbe/ticket/15992 (which is rebased on 6.2.beta5)

Test report:

./sage -t -p --all --long --logfile=logs/ptestlong-alle4.log
...
All tests passed!

[ohanar]

Replying to wluebbe:

2to3 has found nothing for the long integer literal (suffix "L").
13 modules were found with regexp search (r"\s (0\d+) [\s)]"). The result file is attached.

• 6 pyx modules from sage/rings/padics contain code like (1L << (sizeof(long) * 8 - 2)) - 1. I do not whether these should be changed.

These should be fine, long integer literals are important to C and hence you cannot always drop them in Cython code (even for Cython written specifically written for Python 3).

• 4 modules had doc-test with stuff like 4561L # 32-bit. Perhaps these test can be made more tolerant.

How do you propose? The issue is that the Cython code is likely written with 64-bit integers, which on 32-bit platforms cannot always be placed into a Python2 int (since they are just a simple wrapper for the underlying platforms C long). In general you will get this issue when dealing with large integers, it is just mostly avoid in sage since we usually return Sage integers instead of Python ints or longs.

[wluebbe]

I was thinking about #doctest: +ELLIPSIS and replacing 4561L # 32-bit by 4561... # 32-bit.

I hope this would not run counter the purpose of the test :-)

[ohanar]

Replying to wluebbe:

I was thinking about #doctest: +ELLIPSIS and replacing 4561L # 32-bit by 4561... # 32-bit.

I think ... is too liberal, e.g. the follow function would pass this doctest:

def foo():
    print("4561"+"lots of other text"*1000)

[wluebbe]

How about adding some magic number as a sentinel after 4561L?

E.g change

            sage: mm[1]
            10009             # 64-bit
            10009L            # 32-bit

into

            sage: mm[1], 314159
            (10009, 314159)             # 64-bit
            (10009L, 314159)            # 32-bit

[wluebbe]

Of course I meant (10009..., 314159) # 32-bit :-/

[ohanar]

I would rather just wrapping the offending doctests with Integer and providing a comment on why the seemingly unnecessary Integer wrap is there.

[wluebbe]

More complete search result for long integer literals

[wluebbe]

The first search was incomplete. A lot more \d+L instances found (see new attachment).

I guess "fix_long" ticket:16072 (stage 2) should be solved first. That will clarify the approach to be selected here.

Move to stage 2?

[vbraun]

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