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How can I use UUIDs in SQLAlchemy?
... dialect supports UUID columns. This is easy (and the question is specifically postgres) -- I don't understand why the other answers are all so complicated.
Here is an example:
from sqlalchemy.dialects.postgresql import UUID
from flask_sqlalchemy import SQLAlchemy
import uuid
db = SQLAlchemy()
...
How do I sort an observable collection?
...the end of the sorted partition from the unsorted. Worst case O(n). Essentially a selection sort (See below for output).
public static void Sort<T>(this ObservableCollection<T> collection)
where T : IComparable<T>, IEquatable<T>
{
List<T> sorted = co...
ImportError in importing from sklearn: cannot import name check_build
...
Worked for me after installing scipy.
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Is it possible to create static classes in PHP (like in C#)?
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You can have static classes in PHP but they don't call the constructor automatically (if you try and call self::__construct() you'll get an error).
Therefore you'd have to create an initialize() function and call it in each method:
<?php
class Hello
{
private static...
What does __FILE__ mean in Ruby?
I see this all the time in Ruby:
4 Answers
4
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When to use dynamic vs. static libraries
...update is considered binary compatible with the original version.
Additionally dynamic libraries aren't necessarily loaded -- they're usually loaded when first called -- and can be shared among components that use the same library (multiple data loads, one code load).
Dynamic libraries were consid...
How to copy a row and insert in same table with a autoincrement field in MySQL?
....)
select c1, c2, ...
from your_table
where id = 1
where c1, c2, ... are all the columns except id. If you want to explicitly insert with an id of 2 then include that in your INSERT column list and your SELECT:
insert into your_table (id, c1, c2, ...)
select 2, c1, c2, ...
from your_table
where i...
What is the copy-and-swap idiom?
...s arguably the most nuanced and difficult. How should it be done? What pitfalls need to be avoided?
The copy-and-swap idiom is the solution, and elegantly assists the assignment operator in achieving two things: avoiding code duplication, and providing a strong exception guarantee.
How does it wor...
How to measure time in milliseconds using ANSI C?
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Doesn't this measure cpu time and not wall time?
– krs013
Feb 1 '15 at 4:53
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How do I get the opposite (negation) of a Boolean in Python?
...ful if you want to use a function that requires a predicate-function or a callback.
For example map or filter:
>>> lst = [True, False, True, False]
>>> list(map(operator.not_, lst))
[False, True, False, True]
>>> lst = [True, False, True, False]
>>> list(filter...