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How to shuffle a std::vector?
...n Coliru
Make sure to reuse the same instance of rng throughout multiple calls to std::shuffle if you intend to generate different permutations every time!
Moreover, if you want your program to create different sequences of shuffles each time it is run, you can seed the constructor of the random e...
How do I find where an exception was thrown in C++?
I have a program that throws an uncaught exception somewhere. All I get is a report of an exception being thrown, and no information as to where it was thrown. It seems illogical for a program compiled to contain debug symbols not to notify me of where in my code an exception was generated.
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namedtuple and default values for optional keyword arguments
...lds)
>>> Node()
Node(val=None, left=None, right=None)
Order
In all versions of Python, if you set fewer default values than exist in the namedtuple, the defaults are applied to the rightmost parameters. This allows you to keep some arguments as required arguments.
>>> Node.__ne...
Will the base class constructor be automatically called?
... age of customer be 2? It seems like the base class's constructor will be called no matter what. If so, why do we need to call base at the end sometimes?
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Fastest way to get the first object from a queryset in django?
...eturn None if there aren't any. There are lots of ways to do this which all work. But I'm wondering which is the most performant.
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from jquery $.ajax to angular $http
...
$http.patch()
$http.put()
One of the Example:
$http.get("sample.php")
.success(function(response) {
$scope.getting = response.data; // response.data is an array
}).error(){
// Error callback will trigger
});
http://www.drtuts.com/ajax-requests-angula...
Django: How to completely uninstall a Django app?
What is the procedure for completely uninstalling a Django app, complete with database removal?
5 Answers
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Complete Working Sample of the Gmail Three-Fragment Animation Scenario?
...at I'll refer to as "the Gmail three-fragment animation" scenario. Specifically, we want to start with two fragments, like this:
...
How do write IF ELSE statement in a MySQL query
...
you must write it in SQL not it C/PHP style
IF( action = 2 AND state = 0, 1, 0 ) AS state
for use in query
IF ( action = 2 AND state = 0 ) THEN SET state = 1
for use in stored procedures or functions
...
Principal component analysis in Python
...
Months later, here's a small class PCA, and a picture:
#!/usr/bin/env python
""" a small class for Principal Component Analysis
Usage:
p = PCA( A, fraction=0.90 )
In:
A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 colum...