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Chaining multiple filter() in Django, is this a bug?
I always assumed that chaining multiple filter() calls in Django was always the same as collecting them in a single call.
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Get integer value from string in swift
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Instead of putting ! on the call, you can declare your variable as optional: someNumb: Int? = stringNumber.toInt(). Then the type safety system will be aware that foo may not exist. Putting ! will of course crash if your string can't convert to a number....
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: <...
Python String and Integer concatenation [duplicate]
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Backticks are all sorts of silly.
– habnabit
May 17 '10 at 8:58
3
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How to Get True Size of MySQL Database?
...ld the table from scratch. When databases store information on disks, they allocate it in blocks; deleting a record often frees a block between used blocks, and it's very expensive to shift all of the other blocks around to use that space up so it is marked as "free". The space may be used later by ...
How do I avoid capturing self in blocks when implementing an API?
...ied inside the block (we're not doing that) but also they are not automatically retained when the block is retained (unless you are using ARC). If you do this, you must be sure that nothing else is going to try to execute the block after the MyDataProcessor instance is released. (Given the structure...
Why prefer two's complement over sign-and-magnitude for signed numbers?
...o add them.
Two's complement addition is very simple. You add numbers normally and any carry bit at the end is discarded. So they're added as follows:
0010
+ 1111
=10001
= 0001 (discard the carry)
0001 is 1, which is the expected result of "2+(-1)".
But in your "intuitive" method, adding is m...
How can I disable a button in a jQuery dialog from a function?
...tinue" button. I would like this "continue" button to only be enabled once all the fields have content in them, else it will remain disabled.
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Filter dict to contain only certain keys?
...I'm only interested in a select few of them. Is there an easy way to prune all the other ones out?
15 Answers
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Validating URL in Java
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The java.net.URL class is in fact not at all a good way of validating URLs. MalformedURLException is not thrown on all malformed URLs during construction. Catching IOException on java.net.URL#openConnection().connect() does not validate URL either, only tell wether ...