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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 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...
Remove all special characters from a string [duplicate]
I am facing an issue with URLs, I want to be able to convert titles that could contain anything and have them stripped of all special characters so they only have letters and numbers and of course I would like to replace spaces with hyphens.
...
Matplotlib transparent line plots
I am plotting two similar trajectories in matplotlib and I'd like to plot each of the lines with partial transparency so that the red (plotted second) doesn't obscure the blue.
...
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']
share
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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...
How to jump to a particular line in a huge text file?
Are there any alternatives to the code below:
16 Answers
16
...
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...
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...