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How to select last two characters of a string
I need to select last two characters from the variable, whether it is digit or letters.
9 Answers
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Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
...ata.frame(a = 1:3, b=letters[1:3])
require(sqldf)
a1NotIna2 <- sqldf('SELECT * FROM a1 EXCEPT SELECT * FROM a2')
And the rows which are in both data frames:
a1Ina2 <- sqldf('SELECT * FROM a1 INTERSECT SELECT * FROM a2')
The new version of dplyr has a function, anti_join, for exactly the...
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...n a Web Project in Visual Studio 2008. When I hit F12 (or right-click and select Go To Definition) Visual Studio is consistently going to the Metadata file instead of going to the source.
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How do I perform the SQL Join equivalent in MongoDB?
...background as well, I would appreciate MongoDB taking a 'result set' (with selected returned fields) as input for a new query in one go, much like nested queries in SQL
– Stijn Sanders
Nov 26 '10 at 23:17
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More elegant “ps aux | grep -v grep”
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@kxsong: | grep '[t]erminal' selects any line containing the word 'terminal' without putting the word 'terminal' into the process list. What are you trying to achieve with | grep '[r]oot' and how is it not working? There is likely to be a better solution...
Explicitly select items from a list or tuple
...lution.I don't think it's a bad idea to invoke magic variable. programmer selects their preferred way based on programming circumstances.
– Jacob CUI
Mar 25 '15 at 22:57
add ...
Detecting taps on attributed text in a UITextView in iOS
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It doesn't seem to work, when you have not-selectable UITextView
– Paul Brewczynski
Mar 2 '14 at 22:37
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sho...
Cannot generate iOS App archive in xcode
...using your archive to create an archive file rather than an ipa do this:
Select the archive and click the Distribute button.
Select the 'Save Built Products' option.
Hit Next and Save.
Browse the created directory in Finder.
The 'libraries' subdirectory will identify the libraries that you nee...
Django filter queryset __in for *every* item in list
...query:
In [17]: print Photo.objects.filter(tags=t1).filter(tags=t2).query
SELECT "test_photo"."id"
FROM "test_photo"
INNER JOIN "test_photo_tags" ON ("test_photo"."id" = "test_photo_tags"."photo_id")
INNER JOIN "test_photo_tags" T4 ON ("test_photo"."id" = T4."photo_id")
WHERE ("test_photo_tags"."ta...
mongodb: insert if not exists
...what data you want to write:
data = {"$set":{"key2":"value2"}}
Now your selected document will update the value of "key2" only and leave everything else untouched.
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