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Check if a given key already exists in a dictionary
...stead. It sounds like it will do everything you want.
>>> d = {'foo':'bar'}
>>> q = d.setdefault('foo','baz') #Do not override the existing key
>>> print q #The value takes what was originally in the dictionary
bar
>>> print d
{'foo': 'bar'}
>>> r = d.s...
How do I add the contents of an iterable to a set?
...
You can add elements of a list to a set like this:
>>> foo = set(range(0, 4))
>>> foo
set([0, 1, 2, 3])
>>> foo.update(range(2, 6))
>>> foo
set([0, 1, 2, 3, 4, 5])
share
...
How to execute a raw update sql with dynamic binding in rails
...n say this:
ActiveRecord::Base.connection.execute(<<-EOQ)
UPDATE foo
SET bar = #{ActiveRecord::Base.connection.quote(baz)}
EOQ
Note if you're in a Rails migration or an ActiveRecord object you can shorten that to:
connection.execute(<<-EOQ)
UPDATE foo
SET bar = #{co...
Does Python have an ordered set?
...te a dict, then simply ask for the keys() back.
>>> keywords = ['foo', 'bar', 'bar', 'foo', 'baz', 'foo']
>>> list(dict.fromkeys(keywords))
['foo', 'bar', 'baz']
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|
improve...
How to reference constants in EL?
...ported via ImportHandler#importClass() and be available as ${YourConstants.FOO}.
Note that all java.lang.* classes are already implicitly imported and available like so ${Boolean.TRUE} and ${Integer.MAX_VALUE}. This only requires a more recent Java EE 7 container server as early versions had bugs i...
Angularjs - ng-cloak/ng-show elements blink
...have the following markup
<ul class="nav">
<li><a href="/foo" ng-cloak>{{bar}}</a></li>
</ul>
and you happen to be using bootstrap.css, the following selector is more specific for your ng-cloak'ed element
.nav > li > a {
display: block;
}
So if you...
What is reflection and why is it useful?
...give you a code example of this in Java (imagine the object in question is foo) :
Method method = foo.getClass().getMethod("doSomething", null);
method.invoke(foo, null);
One very common use case in Java is the usage with annotations. JUnit 4, for example, will use reflection to look through your...
Add unique constraint to combination of two columns
...
GO
-- succeeds:
INSERT dbo.Person(Name, Active, PersonNumber)
VALUES(N'foo', 1, 22);
GO
-- succeeds:
INSERT dbo.Person(Name, Active, PersonNumber)
VALUES(N'foo', 0, 22);
GO
-- fails:
INSERT dbo.Person(Name, Active, PersonNumber)
VALUES(N'foo', 1, 22);
GO
Data in the table after all of th...
Can a Windows batch file determine its own file name?
... called the batch file. So, if you are at a prompt in D:\dir1 and enter Y:\foo\bar.bat, if bar.bat has @echo %cd% then it will output D:\dir1.
– Preacher
Jun 28 '18 at 21:56
a...
What are the uses of “using” in C#?
...
using, in the sense of
using (var foo = new Bar())
{
Baz();
}
Is actually shorthand for a try/finally block. It is equivalent to the code:
var foo = new Bar();
try
{
Baz();
}
finally
{
foo.Dispose();
}
You'll note, of course, that the first snippet...