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What's the difference between eval, exec, and compile?
...UE <- return top of stack
'single' is a limited form of 'exec' which accepts a source code containing a single statement (or multiple statements separated by ;) if the last statement is an expression statement, the resulting bytecode also prints the repr of the value of th...
Which CheckedListBox event triggers after a item is checked?
...g with. The accepted answer only works in cases while the logic can be performed within the event handler, or something called directly from the event handler. This was not the case for me. Thanks for this awesome yet simple solution.
– Jesse
Feb 10 '17 at 1...
The name 'InitializeComponent' does not exist in the current context
...hasn't been chosen, but this is it and I ran into this coding some Xamarin.Forms.
– Marcus Shockley
Oct 16 '14 at 13:12
1
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CSS media queries: max-width OR max-height
...{ ... }
The long answer.
There's a lot here, but I've tried to make it information dense, not just fluffy writing. It's been a good chance to learn myself! Take the time to systematically read though and I hope it will be helpful.
Media Queries
Media queries essentially are used in web design ...
C++ equivalent of StringBuffer/StringBuilder?
...eam or just plain string concatenations. C++ strings are mutable so the performance considerations of concatenation are less of a concern.
with regards to formatting, you can do all the same formatting on a stream, but in a different way, similar to cout. or you can use a strongly typed functor whi...
Open file dialog box in JavaScript
...is will cause IE to throw an error if you end up submitting the associated form programmatically as well.
– Ray Nicholus
Oct 22 '13 at 21:48
...
Begin, Rescue and Ensure in Ruby?
...rror, ScriptError, Interrupt, SignalException or SystemExit.)
Some blocks form implicit exception blocks. For example, method definitions are implicitly also exception blocks, so instead of writing
def foo
begin
# ...
rescue
# ...
end
end
you write just
def foo
# ...
rescue
# ...
Can I make the foreign key field optional in Django model
...ent because typically if you're going to allow a field to be blank in your form, you're going to also need your database to allow NULL values for that field. The exception is CharFields and TextFields, which in Django are never saved as NULL. Blank values are stored in the DB as an empty string (''...
How to check if a string is a valid date
... real life as you force the caller to check for nil, eg. particularly when formatting. If you return a default date|error it may be friendlier.
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iPad keyboard will not dismiss if modal ViewController presentation style is UIModalPresentationForm
...r reasoning is that the user is often going to be entering data in a modal form so they are trying to be "helpful" and keep the keyboard visible where ordinarily various transitions within the modal view can cause the keyboard to show/hide repeatedly.
edit: here is the response of an Apple engineer...