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enum - getting value of enum on string conversion
...at:
print(D.x.value)
See the Programmatic access to enumeration members and their attributes section:
If you have an enum member and need its name or value:
>>>
>>> member = Color.red
>>> member.name
'red'
>>> member.value
1
You could add a __str__ meth...
How to change Rails 3 server default port in develoment?
...t - do not edit anything in your gem path! It will influence all projects, and you will have a lot problems later...
In your project edit script/rails this way:
#!/usr/bin/env ruby
# This command will automatically be run when you run "rails" with Rails 3 gems installed from the root of your appli...
When to use valueChangeListener or f:ajax listener?
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The valueChangeListener will only be invoked when the form is submitted and the submitted value is different from the initial value. It's thus not invoked when only the HTML DOM change event is fired. If you would like to submit the form during the HTML DOM change event, then you'd need to add an...
Get a filtered list of files in a directory
...noticed that the Python docs say glob() "is done by using the os.listdir() and fnmatch.fnmatch() functions in concert, and not by actually invoking a subshell". In other words, glob() doesn't have the efficiency improvements one might expect.
– Ben Hoyt
Feb 11 ...
Python's os.makedirs doesn't understand “~” in my path
...
You need to expand the tilde manually:
my_dir = os.path.expanduser('~/some_dir')
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Thread.Sleep replacement in .NET for Windows Store
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Windows Store apps embrace asynchrony - and an "asynchronous pause" is provided by Task.Delay. So within an asynchronous method, you'd write:
await Task.Delay(TimeSpan.FromSeconds(30));
... or whatever delay you want. The asynchronous method will continue 30 sec...
JPA CascadeType.ALL does not delete orphans
...o use Hibernate, you'll have to explicitly first delete the child elements and then delete the main record to avoid any orphan records.
execution sequence
fetch main row to be deleted
fetch child elements
delete all child elements
delete main row
close session
With JPA 2.0, you can now use t...
How do I calculate a point on a circle’s circumference?
... r * cos(a)
y = cy + r * sin(a)
Where r is the radius, cx,cy the origin, and a the angle.
That's pretty easy to adapt into any language with basic trig functions. Note that most languages will use radians for the angle in trig functions, so rather than cycling through 0..360 degrees, you're cycli...
Purge Kafka Topic
...t>:2181 --alter --topic <topic name> --config retention.ms=1000
And in newer Kafka releases, you can also do it with kafka-configs --entity-type topics
kafka-configs.sh --zookeeper <zkhost>:2181 --entity-type topics --alter --entity-name <topic name> --add-config retention.ms...
Why can't yield return appear inside a try block with a catch?
...eld return part itself doesn't throw an exception (precalculate the value, and then you're just setting a field and returning "true")
You're allowed try/catch which doesn't use yield return in an iterator block.
All local variables in the iterator block are instance variables in the generated type, ...