Python 3 preparation: Change syntax of raise statement

[wluebbe]

Only the modern syntax like raise E(V) and raise E(V).with_traceback(T) is accepted by Python 3.

Almost all cases change raise E, V to raise E(V) where V is a string.

TODO:

• Clarify why the cases with_traceback were omitted in libfuturize/fixes/raise.py. (Perhaps this belongs to stage 2?)

Changes according to lib2to3/fixes/fix_raise.py:

raise         -> raise
raise E       -> raise E
raise E, V    -> raise E(V)
raise E, V, T -> raise E(V).with_traceback(T)
raise E, None, T -> raise E.with_traceback(T)

raise (((E, E'), E''), E'''), V -> raise E(V)
raise "foo", V, T               -> warns about string exceptions

CAVEATS:
   "raise E, V" will be incorrectly translated if V is an exception
   instance. The correct Python 3 idiom is
       raise E from V
   but since we can't detect instance-hood by syntax alone and since
   any client code would have to be changed as well, we don't automate
   this.

CC: @tscrim

Component: distribution

Author: Wilfried Luebbe

Branch/Commit: 136948a

Reviewer: R. Andrew Ohana

Issue created by migration from https://trac.sagemath.org/ticket/15990

[wluebbe]

Branch: u/wluebbe/ticket/15990

[wluebbe]

Commit: 9db8c5c

[wluebbe]

Failed doc test in sage.doctest.forker.SageDocTestRunner.report_unexpected_exception

[wluebbe]

comment:3

Attachment: failed-doctest-15990-SageDocTestRunner-line1206.txt

In more than 500 py modules the raise statement was (simply) changed to the new syntax.

All doctest succeeded but one (see attachment):

./sage -t -p --all --logfile=logs/ptestlong-15990l-2.log
...
----------------------------------------------------------------------
sage -t src/sage/doctest/forker.py  # 1 doctest failed

I have no idea why ...

[sagetrac-git]

Changed commit from 9db8c5c to 67ec208

[sagetrac-git]

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

67ec208

first run of futurize -w -f raise

[ohanar]

comment:5

If you can update the branch, I can maybe see if I can figure out what is going wrong in the forker.

[sagetrac-git]

Changed commit from 67ec208 to 3279bdc

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

3279bdc

first run of futurize -w -f raise

[wluebbe]

comment:7

Rebased on 6.2.beta6 and resolved merge conflicts.

[ohanar]

comment:8

It looks like it is just a bug in the doctest (it is testing the debugger, so the actual source code ends up being in the output to check).

Otherwise, looks good. (Hopefully this will get merged ASAP before it there are a ton of conflicts again).

---

New commits:

f66c582

fix doctest for trac #15990

[ohanar]

Reviewer: R. Andrew Ohana

[ohanar]

Author: Wilfried Luebbe

[ohanar]

Changed branch from u/wluebbe/ticket/15990 to u/ohanar/raise_statement

[ohanar]

Changed commit from 3279bdc to f66c582

[vbraun]

comment:9

File "src/sage/combinat/designs/ext_rep.py", line 737, in sage.combinat.designs.ext_rep.XTree.__getitem__
Failed example:
    xt.__getitem__(119)
Expected:
    Traceback (most recent call last):
    ...
    IndexError: XTree<blocks> has no index 119
Got:
    <BLANKLINE>
    Traceback (most recent call last):
      File "/home/release/Sage/local/lib/python2.7/site-packages/sage/doctest/forker.py", line 480, in _run
        self.execute(example, compiled, test.globs)
      File "/home/release/Sage/local/lib/python2.7/site-packages/sage/doctest/forker.py", line 839, in execute
        exec compiled in globs
      File "<doctest sage.combinat.designs.ext_rep.XTree.__getitem__[4]>", line 1, in <module>
        xt.__getitem__(Integer(119))
      File "/home/release/Sage/local/lib/python2.7/site-packages/sage/combinat/designs/ext_rep.py", line 745, in __getitem__
        raise IndexError('%s no index %s' % (self.__repr__(), `i`))
    IndexError: XTree<blocks> no index 119

[sagetrac-git]

Changed commit from f66c582 to 79b6367

[sagetrac-git]

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

79b6367

fix rebase error in 3279bdc

[vbraun]

comment:17

Merge conflicts, you'll probably have to wait for the next beta and merge that in.

[vbraun]

comment:18

You can now merge in beta7

[wluebbe]

comment:19

After resolving merge conflicts still tests OK

All tests passed!
----------------------------------------------------------------------
Total time for all tests: 2417.5 seconds
    cpu time: 8135.6 seconds

---

New commits:

16a0f91

Merge branch 'develop' into u/wluebbe/ticket/15990

[wluebbe]

Changed branch from u/ohanar/raise_statement to u/wluebbe/ticket/15990

[wluebbe]

Changed commit from d4dc734 to 16a0f91

[vbraun]

comment:20

Conflicts again with #15148 and #11726 which I already merged after beta7

[wluebbe]

Changed commit from 16a0f91 to none

[wluebbe]

Changed branch from u/wluebbe/ticket/15990 to u/wluebbe/ticket/15990b

[wluebbe]

comment:21

I merged with ticket:15148 and ticket:11726 and tested.

Will it merge now :-/

[vbraun]

comment:22

Your branch doesn't exist...

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1 and set ticket back to needs_review. Last 10 new commits:

e07c76e	Merge branch 'public/ticket/11726' of trac.sagemath.org:sage into 11726
eb09160	trac #11726 implement floordiv for laurent polys in one variable
e27a420	trac #11726 one failing doctest corrected
ba866ef	Merge branch 'public/ticket/11726' into raise-plus
86261b1	Improve count_points
55cdcf3	Refactor point counting code for hyperelliptic curves.
fc7a569	First bunch of fixes and missing examples.
63bf717	Rebase on top of #15108.
8029bc6	Merge remote-tracking branch 'trac/develop' into ticket/15148
136948a	Merge branch 'u/jpflori/ticket/15148' into raise-plus

[sagetrac-git]

Commit: 136948a

[wluebbe]

comment:24

Aaargh! I didn't push ...

[tscrim]

comment:25

Merges cleanly.

[vbraun]

Changed branch from u/wluebbe/ticket/15990b to 136948a