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Drop data frame columns by name
...DF) %in% drops)]
Or, alternatively, you can make a list of those to keep and refer to them by name :
keeps <- c("y", "a")
DF[keeps]
EDIT :
For those still not acquainted with the drop argument of the indexing function, if you want to keep one column as a data frame, you do:
keeps <- "y"
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SET NAMES utf8 in MySQL?
...g by default from client connections (many are, depending on your location and platform.)
Read http://www.joelonsoftware.com/articles/Unicode.html in case you aren't aware how Unicode works.
Read Whether to use "SET NAMES" to see SET NAMES alternatives and what exactly is it about.
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AutoMapper vs ValueInjecter [closed]
...ueInjecter, I can tell you that I did it because I wanted something simple and very flexible
I really don't like writing much or writing lots of monkey code like:
Prop1.Ignore, Prop2.Ignore etc.
CreateMap<Foo,Bar>(); CreateMap<Tomato, Potato>(); etc.
ValueInjecter is something like ...
How can I remove the first line of a text file using bash/sed script?
...you the last 5 lines of the input. The + sign kind of inverts the argument and make tail print anything but the first x-1 lines. tail -n +1 would print the whole file, tail -n +2 everything but the first line, etc.
GNU tail is much faster than sed. tail is also available on BSD and the -n +2 flag i...
Purpose of Django setting ‘SECRET_KEY’
...ly is the point of the SECRET_KEY in django? I did a few google searches and checked out the docs ( https://docs.djangoproject.com/en/dev/ref/settings/#secret-key ), but I was looking for a more in-depth explanation of this, and why it is required.
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How to set environment variable for everyone under my linux system?
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man 8 pam_env
man 5 pam_env.conf
If all login services use PAM, and all login services have session required pam_env.so in their respective /etc/pam.d/* configuration files, then all login sessions will have some environment variables set as specified in pam_env's configuration file.
On ...
Break out of a While…Wend loop
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Another option would be to set a flag variable as a Boolean and then change that value based on your criteria.
Dim count as Integer
Dim flag as Boolean
flag = True
While flag
count = count + 1
If count = 10 Then
'Set the flag to false '
flag = fal...
How do I solve the INSTALL_FAILED_DEXOPT error?
I am developing an Android application using Android 2.2, my application APK size is 22.5 MB, and I would like to create a new build for a Samsung tablet. I got the following error:
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warning: refname 'HEAD' is ambiguous
I am new to Git and I seem to have one branch too many if I execute the following command:
5 Answers
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Is there a Java standard “both null or equal” static method?
To save some typing and clarify my code, is there a standard version of the following method?
3 Answers
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