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How to rename a single column in a data.frame?
...ch - This doesn't seem to work if the column name is something like "A,B,C,m>X m>,Y,Z" where I want to rename it to Y using testData[379] <- "Y".
– Chetan Arvind Patil
Jan 17 '19 at 16:10
...
What reason is there to use null instead of undefined in JavaScript?
...ou might sometimes get an object while undefined means that no object was em>x m>pected (or that there was an error). My problem with that is its completely arbitrary, and totally unnecessary.
That said, there is one major difference - variables that aren't initialized (including function parameters wh...
What is null in Java?
...s an instanceof.
15.20.2 Type Comparison Operator instanceof
RelationalEm>x m>pression:
RelationalEm>x m>pression instanceof ReferenceType
At run time, the result of the instanceof operator is true if the value of the RelationalEm>x m>pression is not null and the reference could be cast to the Referen...
Is nested function a good approach when required by only one function? [closed]
...
>>> def sum(m>x m>, y):
... def do_it():
... return m>x m> + y
... return do_it
...
>>> a = sum(1, 3)
>>> a
<function do_it at 0m>x m>b772b304>
>>> a()
4
Is this what you were looking for? It's ca...
jQuery UI dialog positioning
...ying to use the jQuery dialog UI library in order to position a dialog nem>x m>t to some tem>x m>t when it is hovered over. The jQuery dialog takes a position parameter which is measured from the top left corner of the current viewport (in other words, [0, 0] will always put it in the upper left hand cor...
How can I configure Logback to log different levels for a logger to different destinations?
...warn and error messages to stderr, and everything else to stdout.
logback.m>x m>ml
<appender name="stdout" class="ch.qos.logback.core.ConsoleAppender">
<target>System.out</target>
<filter class="com.foo.StdOutFilter" />
...
</appender>
<appender name="stderr" cl...
What is the “->” PHP operator called and how do you say it when reading code out loud? [closed]
...
Note that the lem>x m>ical token is not always what that token is usually referred to. For em>x m>ample, ::'s name is the "scope resolution operator" but is listed in that article as T_DOUBLE_COLON. I'll +1 to you when I get some more votes :)
...
open read and close a file in 1 line of code
...n will do it automatically either during garbage collection or at program em>x m>it. But as @delnan noted, it's better practice to em>x m>plicitly close it for various reasons.
So, what you can do to keep it short, simple and em>x m>plicit:
with open('pagehead.section.htm','r') as f:
output = f.read()
Now ...
How to filter files when using scp to copy dir recursively?
...ably recommend using something like rsync for this due to its include and em>x m>clude flags, e.g:-
rsync -rav -e ssh --include '*/' --include='*.class' --em>x m>clude='*' \
server:/usr/some/unknown/number/of/sub/folders/ \
/usr/project/backup/some/unknown/number/of/sub/folders/
Some other useful flags:
...
How do I find where JDK is installed on my windows machine?
...
If you are using Linum>x m>/Unim>x m>/Mac OS m>X m>:
Try this:
$ which java
Should output the em>x m>act location.
After that, you can set JAVA_HOME environment variable yourself.
In my computer (Mac OS m>X m> - Snow Leopard):
$ which java
/usr/bin/java
$ ls -l /u...