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How do I perform the SQL Join equivalent in MongoDB?
...rect. The new $lookup operator added to the aggregation pipeline is essentially identical to a left outer join:
https://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <...
What do I use for a max-heap implementation in Python?
... amazed that there IS such a built-in solution in heapq. But then it is totally unreasonable that it is NOT even slightly mentioned at all in the official document! WTF!
– RayLuo
Apr 21 '15 at 6:48
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Pass variables to Ruby script via command line
I've installed RubyInstaller on Windows and I'm running IMAP Sync but I need to use it to sync hundreds of accounts. If I could pass these variables to it via command line I could automate the whole process better.
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Select last N rows from MySQL
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But then you just do a php array_reverse() or whatever the equivalent is in your scripting language of choice. The database doesn't need to do that work.
– Joe
Aug 7 '16 at 22:58
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Skip first entry in for loop in python?
....'two','three'.'four'.'five']
for i in mylist[1:]:
print(i)
In python index start from 0, We can use slicing operator to make manipulations in iteration.
for i in range(1,-1):
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what does the __file__ variable mean/do?
I usually just hard-wire these with the actual path. But there is a reason for these statements that determine path at runtime, and I would really like to understand the os.path module so that I can start using it.
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Why is using 'eval' a bad practice?
...d eval have nothing to do with each other. An application that's fundamentally mis-designed is fundamentally mis-designed. eval is no more the root cause of bad design than division by zero or attempting to import a module which is known not to exist. eval isn't insecure. Applications are insecu...
Vertical (rotated) text in HTML table
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After having tried for over two hours, I can safely say that all the method mentioned so far don't work across browsers, or for IE even across browser versions...
For example (top upvoted answer):
filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=0.083); /* IE6,IE7 */
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Is it valid to replace http:// with // in a ?
... we test our sites in Firefox, Safari, IE6, IE7 and Opera. These browsers all understand that URL format.
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How to add include path in Qt Creator?
... line. Really all this does is tell Qt Creator where to look for files to index for auto completion. Your own build system will have to handle the include paths in its own way.
As explained in the Qt Creator Manual, <your path> must be an absolute path, but you can avoid OS-, host- or user-...