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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...
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...
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...
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...
How to optimize for-comprehensions and loops in Scala?
...imes) {
result = body()
count += 1
}
result
}
def foo() : Int= {
loop(5, 0) {
println("Hi")
return 5
}
}
foo()
This prints "Hi" only once.
Note that the return in foo exits foo (which is what you would expect). Since the bracketed expression is a ...