BLD: Suppressing errors while compling pandas/_libs/groupby

[ShaharNaveh]

• ref Error on C Warnings #32163
• tests added / passed
• passes black pandas
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

This are the errors that this PR is getting rid of:

pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_116group_last’:
pandas/_libs/groupby.c:37458:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
37458 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_118group_last’:
pandas/_libs/groupby.c:38233:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
38233 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_120group_last’:
pandas/_libs/groupby.c:39008:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
39008 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_122group_last’:
pandas/_libs/groupby.c:39781:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
39781 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_124group_last’:
pandas/_libs/groupby.c:40563:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
40563 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_128group_nth’:
pandas/_libs/groupby.c:41999:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
41999 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_130group_nth’:
pandas/_libs/groupby.c:42820:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
42820 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_132group_nth’:
pandas/_libs/groupby.c:43641:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
43641 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_134group_nth’:
pandas/_libs/groupby.c:44460:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
44460 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_136group_nth’:
pandas/_libs/groupby.c:45288:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
45288 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_152group_max’:
pandas/_libs/groupby.c:55168:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
55168 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_154group_max’:
pandas/_libs/groupby.c:55970:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
55970 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_156group_max’:
pandas/_libs/groupby.c:56772:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
56772 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_158group_max’:
pandas/_libs/groupby.c:57568:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
57568 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_162group_min’:
pandas/_libs/groupby.c:58985:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
58985 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_164group_min’:
pandas/_libs/groupby.c:59784:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
59784 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_166group_min’:
pandas/_libs/groupby.c:60583:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
60583 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);
      |                              ^~
pandas/_libs/groupby.c: In function ‘__pyx_pf_6pandas_5_libs_7groupby_168group_min’:
pandas/_libs/groupby.c:61376:30: warning: comparison of integer expressions of different signedness: ‘Py_ssize_t’ {aka ‘long int’} and ‘size_t’ {aka ‘long unsigned int’} [-Wsign-compare]
61376 |   __pyx_t_3 = ((!((__pyx_t_2 == __pyx_t_1) != 0)) != 0);

[WillAyd]

Is it possible to get the same result without casting? Maybe labels.shape[0] for memory views?

[ShaharNaveh]

@WillAyd It works!

---

Just so I know for future times, are we trying to avoid casting?

or casting is not possible with memory views?

[WillAyd]

If there's an easily available approach that doesn't require casting then should almost always go that route

[WillAyd]

lgtm if green - @jbrockmendel

[jbrockmendel]

LGTM. Might want to open an issue with cython; i think in theory these are supposed to be equivalent

[WillAyd]

Looks like also part of 3.0 release cython/cython#2992

…

Sent from my iPhone

On Mar 17, 2020, at 6:16 PM, jbrockmendel ***@***.***> wrote:  LGTM. Might want to open an issue with cython; i think in theory these are supposed to be equivalent — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

[ShaharNaveh]

Looks like also part of 3.0 release cython/cython#2992
…
Sent from my iPhone
On Mar 17, 2020, at 6:16 PM, jbrockmendel @.***> wrote:  LGTM. Might want to open an issue with cython; i think in theory these are supposed to be equivalent — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

That's great!

---

In ea678f0 I have added "TODO" notes, to revert this code change.

[jreback]

thanks @MomIsBestFriend