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How to get a random value from dictionary in python
...b': 5}
>>> d.popitem()
('c', 7)
Since the dict doesn't preserve order, by using popitem you get items in an arbitrary (but not strictly random) order from it.
Also keep in mind that popitem removes the key-value pair from dictionary, as stated in the docs.
popitem() is useful to dest...
Real World Example of the Strategy Pattern
... of comments, etc), and in case management doesn't yet know exactly how to order, and may want to experiment with different orderings at a later date. You make an interface (IOrderAlgorithm or something) with an order method, and let an Orderer-object delegate the ordering to a concrete implementati...
Difference between volatile and synchronized in Java
...
The first has to do with controlling when code executes (including the order in which instructions are executed) and whether it can execute concurrently, and the second to do with when the effects in memory of what has been done are visible to other threads. Because each CPU has several levels ...
MySQL indexes - what are the best practices?
...tant to understand what's going on.
Broadly speaking, an index imposes an ordering on the rows of a table.
For simplicity's sake, imagine a table is just a big CSV file. Whenever a row is inserted, it's inserted at the end. So the "natural" ordering of the table is just the order in which rows...
jquery - return value using ajax result on success
...on isSession(selector) {
$.ajax({
type: "POST",
url: '/order.html',
data: ({ issession : 1, selector: selector }),
dataType: "html",
success: function(data) {
// Run the code here that needs
// to access the data returned
...
In which scenario do I use a particular STL container?
...
You now have unordered_map and unordered_set (and their multi variants) which are not in the flow chart but are good picks when you don't care about order but need to find elements by key. Their lookup is usually O(1) instead of O(log n).
...
Does Python have a ternary conditional operator?
... mind that it's frowned upon by some Pythonistas for several reasons:
The order of the arguments is different from those of the classic condition ? a : b ternary operator from many other languages (such as C, C++, Go, Perl, Ruby, Java, Javascript, etc.), which may lead to bugs when people unfamilia...
Are static variables shared between threads?
...ppens-before every action in that thread that comes later in the program's order.
An unlock (synchronized block or method exit) of a monitor happens-before every subsequent lock (synchronized block or method entry) of that same monitor. And because the happens-before relation is transitive, all act...
JSON.Net Self referencing loop detected
...
Add "[JsonIgnore]" to your model class
{
public Customer()
{
Orders = new Collection<Order>();
}
public int Id { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
[JsonIgnore]
public ICollection<Order> Orders { get; set; }
}
...
how to get the one entry from hashmap without iterating
...
Maps are not ordered, so there is no such thing as 'the first entry', and that's also why there is no get-by-index method on Map (or HashMap).
You could do this:
Map<String, String> map = ...; // wherever you get this from
// Ge...