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'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...
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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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...
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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Insert an element at a specific index in a list and return the updated list
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l.insert(index, obj) doesn't actually return anything. It just updates the list.
As ATO said, you can do b = a[:index] + [obj] + a[index:].
However, another way is:
a = [1, 2, 4]
b = a[:]
b.insert(2, 3)
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Do you put unit tests in same project or another project?
...n affect build processes like automated or continuous build.
I don't really know of any pros. Having an extra project (or 10) isn't a con.
Edit: More Info On Build and Shipping
I would further recommend that any automated build process place production and unit tests into different locations....
Shell equality operators (=, ==, -eq)
...nd many other shells) adopted. That's the whole point -- if you have [[ at all, then you can safely assume that all the extensions ksh implemented around it (fnmatch()-style pattern matching, ERE regular expressions with =~, and yes, suppression of string-splitting and filesystem globbing) will be a...
What's Up with Logging in Java? [closed]
...with whatever logging framework is used in the integrated solution); especially valid if you're an API/Framework/OSS and you rely on other packages that use Commons Logging.
Commons Logging because you don't want to "lock down" to a particular logging framework (so instead you lock down to what Comm...
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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Using Git how do I find changes between local and remote
... to fetch new commits from your remote servers.
So, if you have a branch called master and a remote called origin, after running git fetch, you should also have a branch called origin/master. You can then get the git log of all commits that master needs to be a superset of origin/master by doing gi...