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Django select only rows with duplicate field values
... syntax is also how Django interprets you wanting to do a join. So, essentially when you try to filter on that, Django thinks you're trying to do a join with count which obviously doesn't exist. The fix is to specify a name for your annotation result, i.e. annotate(mycount=Count('id')) and then filt...
Python: Tuples/dictionaries as keys, select, sort
...es and so on.
I'd like to organize them in a data structure in Python that allows for easy selection and sorting. My idea was to put them into a dictionary with tuples as keys, e.g.,
...
Peak signal detection in realtime timeseries data
...andard deviations away from some moving mean, the algorithm signals (also called z-score). The algorithm is very robust because it constructs a separate moving mean and deviation, such that signals do not corrupt the threshold. Future signals are therefore identified with approximately the same accu...
What is a mixin, and why are they useful?
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Probably not an issue in this example, but you generally want to put the main base class as the last element within the parenthesis so to create the inheritance chain: Request==>Mixin==>...==>BaseRequest. See here: ianlewis.org/en/mixins-and-python
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ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)
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The ContentList's Set method will not get called when you change a value inside the collection, instead you should be looking out for the CollectionChanged event firing.
public class CollectionViewModel : ViewModelBase
{
public ObservableCollection<E...
Is there a standard way to list names of Python modules in a package?
Is there a straightforward way to list the names of all modules in a package, without using __all__ ?
10 Answers
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Assigning a variable NaN in python without numpy
...aking) be said to be equal to one another -- see What is the rationale for all comparisons returning false for IEEE754 NaN values? for more details and information.
Instead, use math.isnan(...) if you need to determine if a value is NaN or not.
Furthermore, the exact semantics of the == operation...
How do I initialize a TypeScript object with a JSON object
I receive a JSON object from an AJAX call to a REST server. This object has property names that match my TypeScript class (this is a follow-on to this question ).
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Downloading Java JDK on Linux via wget is shown license page instead
...2b6607d096fa80163/jdk-8u131-linux-x64.rpm > jdk-8u112-linux-x64.rpm
In all cases above, subst 'i586' for 'x64' to download the 32-bit build.
-j -> junk cookies
-k -> ignore certificates
-L -> follow redirects
-H [arg] -> headers
curl can be used in place of wget.
UPDATE FOR JDK 7u7...
Why use prefixes on member variables in C++ classes
...before a capital letter in a word is reserved.
For example:
_Foo
_L
are all reserved words while
_foo
_l
are not. There are other situations where leading underscores before lowercase letters are not allowed. In my specific case, I found the _L happened to be reserved by Visual C++ 2005 and ...