DOC: Add %in% operator into compare w r (GH3850) #5875
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| .. ipython:: python | ||
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| s = pd.Series(np.arange(5),index=np.arange(5)[::-1],dtype=np.float32) |
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Why the np.arange(5)[::-1]? Doesn't that make just more complicated for the reader to understand?
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Yeah it would, I was thinking of something...strange.
On 8 January 2014 22:01, Joris Van den Bossche notifications@github.comwrote:
In doc/source/comparison_with_r.rst:
+~~~~~~~~~~~~
+
+A common way to select data in R is using%in%which is defined using the
+functionmatch. The operator%in%is used to return a logical vector
+indicating if there is a match or not:
+
+.. code-block:: r
+
- s <- 0:4
- s %in% c(2,4)
+The :meth:
~pandas.DataFrame.isinmethod is similar to R%in%operator:
+
+.. ipython:: python
+
- s = pd.Series(np.arange(5),index=np.arange(5)[::-1],dtype=np.float32)
Why the np.arange(5)[::-1]? Doesn't that make just more complicated for
the reader to understand?—
Reply to this email directly or view it on GitHubhttps://github.com//pull/5875/files#r8720691
.
Chapman
| .. ipython:: python | ||
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| s = pd.Series(np.arange(5),dtype=np.float32) | ||
| s.apply(lambda x: [2, 4].index(x) if x in [2,4] else np.nan) |
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You're right. pd.match() ignores it's na_sentinal argument, but otherwise it's a 1:1 match.
The _hashtable_algo function it uses seems to be missing at least the int32 case, btw.
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hmm...looks kind of like Index.get_indexer (and the non_unique version). Never even knew this existed. Maybe should open an issue to see use case / doc or deprecate? I don't see it being used anywhere internally
DOC: Add %in% operator into compare w r (GH3850)
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@chappers thanks again! |
Doesn't close #3850 but at least the
%in%operator is now in the comparison with R docs. I've lumped it with thematchfunction since thats the page you see the%in%operator in the R docs http://finzi.psych.upenn.edu/R/library/base/html/match.html.