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Error “The goal you specified requires a project to execute but there is no POM in this directory” a
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Waiting until two async blocks are executed before starting another block
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Explaining Python's '__enter__' and '__exit__'
... some 'cleandown' code executed (think of it as a try-finally block). Some more explanation here.
A useful example could be a database connection object (which then automagically closes the connection once the corresponding 'with'-statement goes out of scope):
class DatabaseConnection(object):
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Returning the product of a list
Is there a more concise, efficient or simply pythonic way to do the following?
14 Answers
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Int division: Why is the result of 1/3 == 0?
... +1 and it always rounds down. int i = .99999999 sets int to 0. More specifically, it takes the integer portion and discards the rest.
– Byron Whitlock
Jan 13 '11 at 21:30
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How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...set that you want to merge into an older existing data set. This is vastly more efficient than individual row upserts and should be preferred whenever practical.
In this case, you typically follow the following process:
CREATE a TEMPORARY table
COPY or bulk-insert the new data into the temp table
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How to prevent auto-closing of console after the execution of batch file
... Yeah this doesn't always work depending on the environment. For a more robust solution see my answer below. Essentially just do set /p exitkey= "Press any key to continue..."
– Steven Mark Ford
Sep 29 '17 at 4:08
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CSS3 Spin Animation
...://developer.mozilla.org/en-US/docs/CSS/Tutorials/Using_CSS_animations for more info
Once you've configured the animation's timing, you need to define the appearance of the animation. This is done by establishing two or more keyframes using the @keyframes at-rule. Each keyframe describes how t...
Swift days between two NSDates
...rent.dateComponents([.day], from: start, to: end).day!
}
The naming feels more Swifty, it's one line, and using the latest dateComponents() method.
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What is the error “Every derived table must have its own alias” in MySQL?
...able and the software needs to know which customers have made purchases at more than one store:
SELECT DISTINCT customer_id, SUM(1)
FROM ( SELECT DISTINCT customer_id, store_id FROM purchases)
GROUP BY customer_id HAVING 1 < SUM(1);
..will break with the error Every derived table must have...