I made a commit and add some comments about the changes : https://github.com/cgabard/sympy/commit/985e8e8251303aeed2763a2956a95f7d0f8f5ac2
There are several changes in addition to those already mentioned : - Some tests in sympy/core/tests/test_evaluate.py rely on `evaluate=False` needs to be updated, - `flatten` in sympy/core/mul.py and `fraction` in sympy/simplify/radsimp.py use `evaluate=False` and rely on the previous behavior. - *test about kernS* : I am not sure what the purpose of this function is, and I do not know what the actual behavior is. All tests are green on my computer with these modifications. On Wednesday, August 23, 2017 at 11:05:01 AM UTC+2, [email protected] wrote: > > Hum, tests are currently running on my computer and some to fail. > > Some only need updates, like sympy/core/tests/test_evaluate.py which > explicitly refer to evaluate = False current behavior. Some other tests > seem to fail without apparent reasons. I will investigate this before doing > a PR. > > Thank you for your reply, > Christophe Gabard > > On Wednesday, August 23, 2017 at 10:48:47 AM UTC+2, Aaron Meurer wrote: >> >> Are there any other tests that fail if you make the change? >> >> I would look into the git history to see what changes added those tests >> if they made any justification for it. It seems to me that evaluate=False >> shouldn't be removing identities, but maybe there was a reason for it. >> >> Aaron Meurer >> >> On Wed, Aug 23, 2017 at 3:58 AM, <[email protected]> wrote: >> >>> Hello everyone, >>> >>> It is my first post and I hope it is the right place to send my >>> question. First I would like to thank all the developers who created this >>> great library. We use it in my company but we encountered a very strange >>> behavior. I wanted to do a PR to correct it but the tests show that this >>> may be voluntary behavior. >>> >>> The problem : even with "evaluate=False" argument, Mul and Add remove >>> identity elements from its arguments. We can see this behavior in tests : >>> >>> >>> https://github.com/sympy/sympy/blob/master/sympy/core/tests/test_arit.py#L1366 >>> >>> def test_suppressed_evaluation(): >>> a = Add(0, 3, 2, evaluate=False) >>> b = Mul(1, 3, 2, evaluate=False) >>> c = Pow(3, 2, evaluate=False) >>> assert a != 6 >>> assert a.func is Add >>> assert a.args == (3, 2) >>> assert b != 6 >>> assert b.func is Mul >>> assert b.args == (3, 2) >>> assert c != 9 >>> assert c.func is Pow >>> assert c.args == (3, 2) >>> >>> Removing arguments is already a kind of evaluation. For me, we should >>> have : >>> >>> def test_suppressed_evaluation(): >>> a = Add(0, 3, 2, evaluate=False) >>> b = Mul(1, 3, 2, evaluate=False) >>> # ... >>> assert a.args == (0, 3, 2) >>> # ... >>> assert b.args == (1, 3, 2) >>> # ... >>> >>> >>> and do not remove any arguments. >>> >>> I can do a PR to change this behavior (and update tests), It seems to me >>> that this can be corrected by moving the lines that remove identities >>> elements right after the "evaluate" processing : move the line >>> https://github.com/sympy/sympy/blob/master/sympy/core/operations.py#L31 >>> after the if on line 33. >>> >>> I prefer to ask the question here before because the presence of the >>> tests can make believe that this behavior is voluntary. >>> >>> Christophe Gabard >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sympy" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/sympy. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/sympy/2b59c125-f424-459b-b5a1-f220e5ef7db2%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/sympy/2b59c125-f424-459b-b5a1-f220e5ef7db2%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> >> -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/dd559b97-3d48-4c6f-ab7a-491f4ac82fdb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
