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Selecting only numeric columns from a data frame
... R's particular quirks, and more straightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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What is the difference between IEqualityComparer and IEquatable?
...s of Person at some point you might require to test equality of two people based on their age. In that case you can do:
class Person
{
public int Age;
}
class AgeEqualityTester : IEqualityComparer<Person>
{
public bool Equals(Person x, Person y)
{
return x.Age == y.Age;
...
How to JSON serialize sets?
...de disappeared
updated the call to the parents' default with super()
using base64 to serialize the bytes type into str (because it seems that bytes in python 3 can't be converted to JSON)
from decimal import Decimal
from base64 import b64encode, b64decode
from json import dumps, loads, JSONEncoder...
What is the difference between `after_create` and `after_save` and when to use which?
...
From the docs:
after_create()
Is called after
Base.save on new objects that haven‘t
been saved yet (no record exists).
after_save()
Is called after Base.save
(regardless of whether it‘s a create
or update save).
...
How to sparsely checkout only one single file from a git repository?
...it doesn't store files as you think (as CVS/SVN do), but it generates them based on the entire history of the project.
But there are some workarounds for specific cases. Examples below with placeholders for user, project, branch, filename.
GitHub
wget https://raw.githubusercontent.com/user/projec...
How to extract the first two characters of a string in shell scripting?
...st efficient method, if you're using the bash shell (and you appear to be, based on your comments), is to use the sub-string variant of parameter expansion:
pax> long="USCAGol.blah.blah.blah"
pax> short="${long:0:2}" ; echo "${short}"
US
This will set short to be the first two characters of...
What's the fastest way to merge/join data.frames in R?
...dea of sqldf is that the data frames in your R session constitute the data base, not the tables in sqlite. Thus each time the code refers to an unqualified table name it will look in your R workspace for it -- not in sqlite's main database. Thus the select statement that was shown reads d1 and d2 ...
Get selected text from a drop-down list (select box) using jQuery
...ng. They're not random at all, they're structural and follow strict rules (based on things like whether you put an ID on your control, and if not then based on the index of where they occur in the current level of the tree, etc)
– freefaller
Mar 9 '17 at 14:03
...
Prevent Caching in ASP.NET MVC for specific actions using an attribute
...);
filterContext.HttpContext.Response.Cache.SetNoStore();
base.OnResultExecuting(filterContext);
}
}
Then just decorate your controller with [NoCache]. OR to do it for all you could just put the attribute on the class of the base class that you inherit your controllers from (i...
How do I overload the square-bracket operator in C#?
... what you're doing, you might find it more appropriate to do: get { return base[i]; } set { base[i] = value; }
– MikeBaz - MSFT
Oct 4 '12 at 21:58
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