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Is there a Python equivalent of the C# null-coalescing operator?
In C# there's a null-coalescing operator (written as ?? ) that allows for easy (short) null checking during assignment:
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How to redirect 404 errors to a page in ExpressJS?
...isionmedia/express/blob/master/examples/error-pages/index.js
So it is actually this part:
// "app.router" positions our routes
// above the middleware defined below,
// this means that Express will attempt
// to match & call routes _before_ continuing
// on, at which point we assume it's a 404...
Stop Mongoose from creating _id property for sub-document array items
If you have subdocument arrays, Mongoose automatically creates ids for each one. Example:
6 Answers
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Linq to Sql: Multiple left outer joins
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This may be cleaner (you dont need all the into statements):
var query =
from order in dc.Orders
from vendor
in dc.Vendors
.Where(v => v.Id == order.VendorId)
.DefaultIfEmpty()
from status
in dc.Status
.Where(...
Getting the last argument passed to a shell script
$1 is the first argument.
$@ is all of them.
27 Answers
27
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UITextView that expands to text using auto layout
I have a view that is laid out completely using auto layout programmatically. I have a UITextView in the middle of the view with items above and below it. Everything works fine, but I want to be able to expand UITextView as text is added. This should push everything below it down as it expands.
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Loop through an array of strings in Bash?
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Note that the double quotes around "${arr[@]}" are really important. Without them, the for loop will break up the array by substrings separated by any spaces within the strings instead of by whole string elements within the array. ie: if you had declare -a arr=("element 1" "ele...
What is a good pattern for using a Global Mutex in C#?
...id );
// Need a place to store a return value in Mutex() constructor call
bool createdNew;
// edited by Jeremy Wiebe to add example of setting up security for multi-user usage
// edited by 'Marc' to work also on localized systems (don't use just "Everyone")
var allowEveryoneRu...
Swift: #warning equivalent
...builds clean in production, but I get a warning in development that essentially reminds me I'm in dev mode - using different URLs, timeouts, other settings etc. Arie's suggestion above lets me do this, your technique just flags everything. That said, this technique has its use for sure so I up voted...
Call a python function from jinja2
I am using jinja2, and I want to call a python function as a helper, using a similar syntax as if I were calling a macro. jinja2 seems intent on preventing me from making a function call, and insists I repeat myself by copying the function into a template as a macro.
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