ENH: Treat 'Inf' as infinity in text parser by jtratner · Pull Request #4220 · pandas-dev/pandas (original) (raw)
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Makes 'inf' checks case insensitive using strcasecmp
Fixes #4219.
was using strcasecmp slower? (prob not a big deal either way)
No. I'm doing that instead. Just found a few other things that needed to be fixed (plus means test cases need to be larger).
Is TestPythonParser supposed to call the parser functions in parsers.pyx?
some of python parser functions are shared
but not sure (your tests are run thru both parsers though so u will know if they work or not)
Okay, I guess I thought engine='python' would set it to pure python only. Not a big deal to me, just wanted to make sure (thought it could have been a bug or something)
@jtratner you are very thorough!
and you said u were busy this week :)
haha ... didn't take long to do so I figured I'd crank it out.
This means that any text that converts to 'inf' when lower cased is considered infinity [though only when attempting to convert column to float/double]. Is that what we want to do?
(e.g., "-iNF", "inf", "inF" all would become versions of +/- infinity)
yes I think any of those variations are fine
it might be easier/faster to make a hash table of all of the combinations and just do a lookup
(this is how na values r done) - but only if u r interested in trying it out - prob not necessary
hmm...I'll think about it. Could probably just reuse the function that creates the hashtable for na_values then. But given that right now it's a 25ish character change in the actual code (import strcasecmp, strcmp-->strcasecmp), this is pretty simple. [just realized I left in the extra (and now unnecessary inf values)]
If you want doc update on this, I can add Monday.
On Thu, Jul 11, 2013 at 10:13 PM, jreback notifications@github.com wrote:
yep looks good to go
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.
hold off on release notes till after 0.12...have to add the new file
Btw - when are you pulling the trigger on 0.12? :)
just a couple minor issues with 0.12rc1...then should be out
Instead of just 'inf' or '-inf', can test for 'Inf', '-Inf', 'INF', etc. Uses strcasecmp under the hood.
(also, small fix to assert_almost_equal to make string comparisons clearer)
@jreback This should be ready to go (just waitin' on Travis).
should 'infinity' be there too?
I'd say no, because that's bordering more on things that could be string-like (not 100% sure: are inf checks are done before dtype decision?). If we did that, would need to switch to hashtable format, which I could do. your call on how you want to do it.
right. so forget that
looks good what u have
can u just do a quick perf test
just run vs 0.12 vbenchs
you can use -r regex to only run some
I some in the io_brench
just to make sure it doesn't slow it down much (I think it'll be fine though)
@jreback is there a way to collect vbench results into a csv?
I find the my results can vary a lot and being able to combine multiple would help smooth it out.
Make sure you're not doing literally anything else when you run test perf. I sometimes forget that and I get "bad" results. Ratio > 1.15 is usually something sketchy but only if you weren't running anything else.
Well anything like building docs or compiling stuff. Surfing the web is OK.
Here are just the "read_*" benches:
*** Processing results...
***
Invoked with :
--ncalls: 3
--repeats: 3
-------------------------------------------------------------------------------
Test name | head[ms] | base[ms] | ratio |
-------------------------------------------------------------------------------
read_store_table | 3.3030 | 4.4127 | 0.7485 |
read_csv_vb | 29.5163 | 37.5853 | 0.7853 |
read_csv_comment2 | 29.8669 | 31.6617 | 0.9433 |
read_table_multiple_date | 295.3293 | 298.5720 | 0.9891 |
read_store | 2.6910 | 2.6627 | 1.0107 |
read_table_multiple_date_baseline | 137.8644 | 135.1160 | 1.0203 |
read_store_table_mixed | 6.5330 | 6.3693 | 1.0257 |
read_parse_dates_iso8601 | 1.7890 | 1.7393 | 1.0286 |
read_store_mixed | 5.8227 | 5.6427 | 1.0319 |
read_csv_thou_vb | 43.4330 | 41.5463 | 1.0454 |
read_store_table_panel | 42.0457 | 40.0033 | 1.0511 |
read_store_table_wide | 21.0853 | 19.6953 | 1.0706 |
read_csv_standard | 18.4487 | 15.5730 | 1.1847 |
-------------------------------------------------------------------------------
Test name | head[ms] | base[ms] | ratio |
-------------------------------------------------------------------------------
Ratio < 1.0 means the target commit is faster then the baseline.
Seed used: 1234
Target [3080721] : ENH: Use case-insensitive checks for 'inf' in parser.
Base [6c8fca9] : Merge pull request #4282 from cpcloud/add-clipboard-test
I just ran the bench against a bogus commit (literally adding whitespace to ez_setup.py) and I get about the same differences just by random chance, so I'm not convinced that these results are particularly meaningful.
e.g. here's against a basically blank commit:
-------------------------------------------------------------------------------
Test name | head[ms] | base[ms] | ratio |
-------------------------------------------------------------------------------
read_store_table_mixed | 6.5234 | 6.8897 | 0.9468 |
read_store_table_panel | 40.2050 | 41.2770 | 0.9740 |
read_store | 2.7483 | 2.7854 | 0.9867 |
read_csv_standard | 15.7667 | 15.9566 | 0.9881 |
read_csv_comment2 | 32.8847 | 33.2080 | 0.9903 |
read_store_table | 3.2610 | 3.2636 | 0.9992 |
read_store_mixed | 5.7760 | 5.6917 | 1.0148 |
read_csv_thou_vb | 43.5576 | 42.8537 | 1.0164 |
read_parse_dates_iso8601 | 1.7897 | 1.7587 | 1.0177 |
read_store_table_wide | 20.0947 | 19.7203 | 1.0190 |
read_table_multiple_date_baseline | 141.1477 | 137.1057 | 1.0295 |
read_table_multiple_date | 317.5010 | 296.3533 | 1.0714 |
read_csv_vb | 34.2953 | 29.2070 | 1.1742 |
-------------------------------------------------------------------------------
Test name | head[ms] | base[ms] | ratio |
-------------------------------------------------------------------------------
perf testing is actually quite tricky as many things can affect it from one run to another - just looking to make sure that the change which we think is a non event really is
so looks good then
jreback added a commit that referenced this pull request
ENH: Treat 'Inf' as infinity in text parser