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Display filename before matching line
... If grep is supplied with multiple file names, it will automatically display the file names before the match, but it will leave the file name out in case of a single input file. By using /dev/null as an extra input file grep "thinks" it dealing with multiple files, but /dev/null is of cou...
'Incomplete final line' warning when trying to read a .csv file into R
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Are you really sure that you selected the .csv file and not the .xls file? I can only reproduce the error if I try to read in an .xls file. If I try to read in a .csv file or any other text file, it's impossible to recreate the error y...
Matching an empty input box using CSS
...e present in the input tag. Tested in Chrome - not sure if this counts for all browsers.
– Berend
Mar 17 '17 at 6:23
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How to send a stacktrace to log4j?
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I never know what to stuff into the first String, usually I just end up doing log.error(e.getLocalizedMessage(), e) which is totally redundant. Does it handle a null for the first argument?
– Mark Peters
Dec 3 '10 at 16:52
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How to install psycopg2 with “pip” on Python?
I'm using virtualenv and I need to install "psycopg2".
33 Answers
33
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How do I replace text inside a div element?
I need to set the text within a DIV element dynamically. What is the best, browser safe approach? I have prototypejs and scriptaculous available.
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How can I convert a comma-separated string to an array?
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Best practice for support all types of strings. See here stackoverflow.com/a/32657055/2632619
– Andi AR
Sep 18 '15 at 16:46
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Why does ContentResolver.requestSync not trigger a sync?
...n I trigger it from the Dev Tools Sync Tester application, however when I call ContentResolver.requestSync(account, authority, bundle) from my ContentProvider, my sync is never triggered.
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How do you do block comments in YAML?
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The syntax differences are subtle and seldom arise in practice: JSON allows extended charactersets like UTF-32, YAML requires a space after separators like comma, equals, and colon while JSON does not, and some non-standard implementations of JSON extend the grammar to include Javascript's /* ...
When should I use a composite index?
...olumn_A )
But it will not (at least not directly, maybe it can help partially if there are no better indices) help for queries that need
index( column_A, column_C )
Notice how column_B is missing.
In your original example, a composite index for two dimensions will mostly benefit queries that q...