大约有 40,000 项符合查询结果（耗时：0.0470秒） [XML]
Convert a row of a data frame to vector
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Might have been changed in the meantime, but today unlist allows dropping names: identical(unlist(df[1,], use.names = FALSE), as.numeric(df[1,])) (and btw df still is not a sensible name for a data.frame... ;-))
– Andri Signorell
Sep 25 '1...
How can I get a precise time, for example in milliseconds in Objective-C?
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Actually this is precise enough for the general use case.
– logancautrell
Jul 2 '12 at 12:30
4
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Splitting templated C++ classes into .hpp/.cpp files--is it possible?
...the implementation of a template class in a separate cpp file and compile. All the ways to do so, if anyone claims, are workarounds to mimic the usage of separate cpp file but practically if you intend to write a template class library and distribute it with header and lib files to hide the implemen...
How to switch to the new browser window, which opens after click on the button?
...ose() closes both windows. It only closes the current. driver.quit() kills all instances. I can see somebody already pointed this out to you. Your comment is full of mistakes. Have a good day.
– silver
Aug 28 '17 at 18:12
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SQL Client for Mac OS X that works with MS SQL Server [closed]
How can I connect to a remote SQL server using Mac OS X? I don't really need a GUI, but it would be nice to have for the color coding and resultset grid. I'd rather not have to use a VM.
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What does in XML mean?
...for the parser to interpret as only character data, not markup."
Syntactically, it behaves similarly to a comment:
<exampleOfAComment>
<!--
Since this is a comment
I can use all sorts of reserved characters
like > < " and &
or write things like
<foo><...
BAT file: Open new cmd window and execute a command in there
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If you're using this to run a rails server you actually don't need to type cmd. You can just type start rails s.
– fbonetti
Jun 27 '13 at 17:51
add a c...
What is the syntax rule for having trailing commas in tuple definitions?
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In all cases except the empty tuple the comma is the important thing. Parentheses are only required when required for other syntactic reasons: to distinguish a tuple from a set of function arguments, operator precedence, or to a...
When should I use the Visitor Design Pattern? [closed]
...want to make the fewest possible modifications to it.
The Visitor pattern allows you to move each new operation in a suitable class, and you need to extend the hierarchy's interface only once. Let's do it. First, we define an abstract operation (the "Visitor" class in GoF) which has a method for ev...
Django TemplateDoesNotExist?
... assuming that you have the apps configured in settings.py like this:
INSTALLED_APPS = (
'appname1',
'appname2',
'appname3',
)
By default Django will load the templates under templates/ directory under every installed apps. So with your directory structure, we want to move our templat...