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MySQL, Check if a column exists in a table with SQL
...pecific column, and if not — create it. Otherwise do nothing. This is really an easy procedure in any enterprise-class database, yet MySQL seems to be an exception.
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How to disable and re-enable console logging in Python?
... If you wanted to only filter message below a certain log level (say, all INFO messages), you could change the second line to something like logger.setLevel(logging.WARNING)
– Hartley Brody
Jan 5 '18 at 16:48
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How to concatenate properties from multiple JavaScript objects
...n Javascript.
The Object.assign() method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.
MDN documentation on Object.assign()
var o1 = { a: 1 };
var o2 = { b: 2 };
var o3 = { c: 3 };
var...
Can I install Python windows packages into virtualenvs?
Virtualenv is great: it lets me keep a number of distinct Python installations so that different projects' dependencies aren't all thrown together into a common pile.
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Function return value in PowerShell
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PowerShell has really wacky return semantics - at least when viewed from a more traditional programming perspective. There are two main ideas to wrap your head around:
All output is captured, and returned
The return keyword really just indi...
How to open a URL in a new Tab using JavaScript or jQuery? [duplicate]
How to open a URL in new tab instead of new window programatically?
6 Answers
6
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Is there an expression for an infinite generator?
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for x in iter(int, 1): pass
Two-argument iter = zero-argument callable + sentinel value
int() always returns 0
Therefore, iter(int, 1) is an infinite iterator. There are obviously a huge number of variations on this particular theme (especially once you add lambda into the mix). One va...
What's the difference between dist-packages and site-packages?
I'm a bit miffed by the python package installation process. Specifically, what's the difference between packages installed in the dist-packages directory and the site-packages directory?
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Get the latest record from mongodb collection
...1 means order opposite of the one that records are inserted in.
Edit: For all the downvoters, above is a Mongoose syntax,
mongo CLI syntax is: db.collectionName.find({}).sort({$natural:-1}).limit(1)
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Calendar Recurring/Repeating Events - Best Storage Method
... didn't want to have a large number of rows, and I wanted to easily lookup all events that would take place on a specific date.
The method below is great at storing repeating information that occurs at regular intervals, such as every day, every n days, every week, every month every year, etc etc. ...