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What is the difference between NaN and None?
... a dictionary. The columns contain strings of numbers and letters. Occasionally there are cases where a cell is empty. In my opinion, the value read to that dictionary entry should be None but instead nan is assigned. Surely None is more descriptive of an empty cell as it has a null value, whe...
What do I have to do to get Core Data to automatically migrate models?
...AndKeys:
[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption,
[NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];
NSError *error;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectMod...
Rails 3: Get Random Record
...; rand(Thing.count))
# Rails 3
Thing.offset(rand(Thing.count)).first
Actually, in Rails 3 all examples will work. But using order RANDOM is quite slow for big tables but more sql-style
UPD. You can use the following trick on an indexed column (PostgreSQL syntax):
select *
from my_table
where i...
SLF4J: Class path contains multiple SLF4J bindings
...
is the version (slf4j-log4j12) applicable for all? or should we find out the version from mvn dependency:tree?
– Lei Yang
Nov 11 '19 at 7:07
add a...
Determining type of an object in ruby
... the "type" of an object, which is a wobbly term in the Ruby world, is to call object.class.
Since classes can inherit from other classes, if you want to determine if an object is "of a particular type" you might call object.is_a?(ClassName) to see if object is of type ClassName or derived from it....
How to remove an HTML element using Javascript?
...em);
return false;
}
But you don't need (or want) a form for that at all, not if its sole purpose is to remove the dummy div. Instead:
HTML:
<input type="button" value="Remove DUMMY" onclick="removeDummy()" />
JavaScript:
function removeDummy() {
var elem = document.getElementBy...
Unit Test? Integration Test? Regression Test? Acceptance Test?
...plicable:
Unit Test
A unit test is performed on a self-contained unit (usually a class or method) and should be performed whenever a unit has been implemented or updating of a unit has been completed.
This means it's run whenever you've written a class/method, fixed a bug, changed functionality......
Convert a Unicode string to a string in Python (containing extra symbols)
...
This breaks if the content of the string is actually unicode, not just ascii characters in a unicode string. Don't do this, you'll get random UnicodeEncodeError exceptions all over the place.
– Doug
Oct 9 '13 at 7:31
...
Do we need semicolon at the end? [duplicate]
...andable manner using examples under the headings:
Where Semicolons are Allowed
Where Semicolons May be Omitted
The rules
It even digs into the official ECMAScript specification about the topic.
share
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How to get the ActionBar height?
...f the ActionBar (using Sherlock) every time an activity is created (specially to handle configuration changes on rotation where the ActionBar height might change).
...