BUG: Fixed to_datetime for array with both Tz-aware datetimes and NaTs

[cancan101]

Closes #5961

[jreback]

pls do a perf check on this
iIIRC a similar bit of code recently had a big git on this

solved by doing

util._checknull or is NaT

full checknull not needed here because u r already know it's not a float

[cancan101]

Okay. I can make that change and then run vbench. FWIW, there are (IMHO) too many version of checknull which leads to errors like this. They are also very poorly documented.

[jreback]

they certainly could be named better !

u know how it does though

u need slightly different versions of a function but code doesn't get cleaned up

can change as long as it doesn't affect t perf (sometimes it is better in cython to manually inline thing FYI ) - though harder 2 read and harder to maintain

[cancan101]

frame_xs_row                                 |   0.0490 |   0.0476 |   1.0301 |
sort_level_zero                              |   4.5211 |   4.3830 |   1.0315 |
timeseries_asof_single                       |   0.0320 |   0.0310 |   1.0333 |
strings_lstrip                               |   2.8183 |   2.7260 |   1.0339 |
reshape_unstack_simple                       |   3.3143 |   3.2057 |   1.0339 |
strings_repeat                               |   3.5940 |   3.4694 |   1.0359 |
timeseries_to_datetime_YYYYMMDD              |   7.7993 |   7.5119 |   1.0383 |
frame_boolean_row_select                     |   0.2743 |   0.2640 |   1.0391 |
timestamp_ops_diff2                          |  20.5154 |  19.7160 |   1.0405 |
plot_timeseries_period                       |  66.7570 |  63.9970 |   1.0431 |
strings_join_split                           |  25.4734 |  24.3703 |   1.0453 |
timeseries_asof                              |   7.1043 |   6.7916 |   1.0460 |
stats_rank_average                           |  27.6279 |  26.4047 |   1.0463 |
strings_slice                                |   2.2720 |   2.1567 |   1.0535 |
frame_iteritems_cached                       |   0.5523 |   0.5236 |   1.0548 |
dti_reset_index                              |   0.2627 |   0.2484 |   1.0576 |
join_dataframe_integer_2key                  |   5.9144 |   5.5893 |   1.0582 |
timeseries_1min_5min_mean                    |   0.6526 |   0.6157 |   1.0600 |
join_dataframe_index_single_key_small        |   6.1546 |   5.7720 |   1.0663 |
series_constructor_ndarray                   |   0.0149 |   0.0140 |   1.0682 |
frame_mult                                   |   5.8010 |   5.4300 |   1.0683 |
frame_html_repr_trunc_si                     |  31.9476 |  29.3944 |   1.0869 |
timeseries_period_downsample_mean            |  10.3723 |   9.5270 |   1.0887 |
stats_rolling_mean                           |   1.0570 |   0.9584 |   1.1029 |
frame_add                                    |   6.0227 |   5.4283 |   1.1095 |
stat_ops_level_series_sum                    |   2.5946 |   2.3270 |   1.1150 |
timestamp_series_compare                     |   2.3543 |   2.0733 |   1.1355 |
dti_reset_index_tz                           |  10.1180 |   8.8783 |   1.1396 |
timestamp_ops_diff1                          |   7.9810 |   6.7777 |   1.1775 |
eval_frame_mult_python_one_thread            |  20.3840 |  16.5833 |   1.2292 |
datetimeindex_unique                         |   0.2013 |   0.1214 |   1.6588 |
timeseries_asof_nan                          |  10.7890 |   6.3873 |   1.6891 |
-------------------------------------------------------------------------------
Test name                                    | head[ms] | base[ms] |  ratio   |
-------------------------------------------------------------------------------

Ratio < 1.0 means the target commit is faster then the baseline.
Seed used: 1234

Target [31537d1] : BUG: Fixed ``to_datetime`` for array with both Tz-aware datetimes and
``NaT``s  (GH5961)
Base   [99910a3] : Merge pull request #5944 from unutbu/str-extract

ENH: Improve perf of str_extract

[cancan101]

and run again (same commit):

timeseries_asof_single                       |   0.0316 |   0.0307 |   1.0311 |
frame_getitem_single_column                  |  18.8413 |  18.2431 |   1.0328 |
reindex_fillna_pad                           |   0.4267 |   0.4127 |   1.0339 |
stat_ops_level_series_sum                    |   2.4223 |   2.3400 |   1.0352 |
timeseries_timestamp_tzinfo_cons             |   0.0117 |   0.0113 |   1.0352 |
frame_fancy_lookup                           |   2.8434 |   2.7457 |   1.0356 |
strings_get                                  |   2.4127 |   2.3274 |   1.0367 |
datetimeindex_unique                         |   0.1171 |   0.1127 |   1.0388 |
match_strings                                |   0.4327 |   0.4160 |   1.0399 |
strings_contains_few_noregex                 |   2.0041 |   1.9246 |   1.0413 |
series_drop_duplicates_string                |   0.4907 |   0.4690 |   1.0461 |
timeseries_to_datetime_YYYYMMDD              |   7.9597 |   7.5970 |   1.0477 |
datetimeindex_infer_dst                      |   3.6183 |   3.4370 |   1.0527 |
datetime_index_union                         |   0.0590 |   0.0560 |   1.0539 |
lib_fast_zip                                 |   8.1453 |   7.7287 |   1.0539 |
dti_reset_index_tz                           |   9.1577 |   8.6746 |   1.0557 |
frame_reindex_columns                        |   0.4126 |   0.3904 |   1.0570 |
packers_write_csv                            | 444.5443 | 420.1533 |   1.0581 |
append_frame_single_homogenous               |   0.2710 |   0.2553 |   1.0616 |
concat_small_frames                          |  12.6719 |  11.8536 |   1.0690 |
datetimeindex_normalize                      |   2.7840 |   2.5953 |   1.0727 |
timeseries_slice_minutely                    |   0.0720 |   0.0670 |   1.0747 |
read_parse_dates_iso8601                     |   1.2953 |   1.2027 |   1.0771 |
eval_frame_chained_cmp_python_one_thread     |  28.6223 |  26.5460 |   1.0782 |
reindex_multiindex                           |   1.4643 |   1.3556 |   1.0801 |
frame_drop_dup_inplace                       |   2.8343 |   2.5744 |   1.1010 |
frame_to_csv_date_formatting                 |  13.4597 |  12.1140 |   1.1111 |
strings_title                                |   3.4863 |   3.1323 |   1.1130 |
eval_frame_mult_one_thread                   |  12.8667 |  11.1853 |   1.1503 |
-------------------------------------------------------------------------------
Test name                                    | head[ms] | base[ms] |  ratio   |
-------------------------------------------------------------------------------

Ratio < 1.0 means the target commit is faster then the baseline.
Seed used: 1234

Target [31537d1] : BUG: Fixed ``to_datetime`` for array with both Tz-aware datetimes and
``NaT``s  (GH5961)
Base   [99910a3] : Merge pull request #5944 from unutbu/str-extract

ENH: Improve perf of str_extract

[jreback]

thanks!