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Python None comparison: should I use “is” or ==?
...ject None, so when you do my_var is None, you're checking whether they actually are the same object (not just equivalent objects)
In other words, == is a check for equivalence (which is defined from object to object) whereas is checks for object identity:
lst = [1,2,3]
lst == lst[:] # This is Tr...
Namespace not recognized (even though it is there)
... page.
This is a problem in Visual Studio (I would even go so far as to call it a bug). AutoMapper requires assemblies that are excluded from the .NET Framework 4 Client Profile. Since your project is using that version of the framework it breaks.
A similar error will propagate to the build pro...
Group by multiple columns in dplyr, using string vector input
...
Does the call to one_of() do anything here? I think it is redundant in this context, as the expression is wrapped in a call to vars().
– knowah
Aug 15 '19 at 14:13
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Passing an integer by reference in Python
...d you can't just assign the "variable" a new value because then you're actually creating a new object (which is distinct from the old one) and giving it the name that the old object had in the local namespace.
Usually the workaround is to simply return the object that you want:
def multiply_by_2(x...
How to check if an email address exists without sending an email?
...here are two methods you can sometimes use to determine if a recipient actually exists:
You can connect to the server, and issue a VRFY command. Very few servers support this command, but it is intended for exactly this. If the server responds with a 2.0.0 DSN, the user exists.
VRFY user
You can...
What's the (hidden) cost of Scala's lazy val?
...nswered Jun 15 '10 at 7:51
oxbow_lakesoxbow_lakes
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How do I size a UITextView to its content?
... Tested on iOS 7 to resize an UITextView into an UITableViewCell. Works really great. This is the only answer that finally worked for me. Thanks!
– Alex
Nov 30 '13 at 18:40
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How to handle dependency injection in a WPF/MVVM application
...rd and it has a good documentation (and plenty of answers on SO).
So basically it goes like this:
Create the view model, and take the IStorage interface as constructor parameter:
class UserControlViewModel
{
public UserControlViewModel(IStorage storage)
{
}
}
Create a ViewModelLoca...
Apply .gitignore on an existing repository already tracking large number of files
...
This answer solved my problem:
First of all, commit all pending changes.
Then run this command:
git rm -r --cached .
This removes everything from the index, then just run:
git add .
Commit it:
git commit -m ".gitignore is now working"
...
What are the GCC default include directories?
...
There is a command with a shorter output, which allows to automatically cut the include pathes from lines, starting with a single space:
$ echo | gcc -Wp,-v -x c++ - -fsyntax-only
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.8.2/include-fixed"
ignori...