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What is the difference between String.Empty and “” (empty string)?
...ich makes string.Empty more efficient.
In version 2.0 and later of .NET, all occurrences of "" refer to the same string literal, which means "" is equivalent to .Empty, but still not as fast as .Length == 0.
.Length == 0 is the fastest option, but .Empty makes for slightly cleaner code.
See the ...
jsonify a SQLAlchemy result set in Flask [duplicate]
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It seems that you actually haven't executed your query. Try following:
return jsonify(json_list = qryresult.all())
[Edit]: Problem with jsonify is, that usually the objects cannot be jsonified automatically. Even Python's datetime fails ;)
Wha...
What is C# analog of C++ std::pair?
...pairTest()
{
string s = "abc";
Pair<int, string> foo = new Pair<int, string>(10, s);
Pair<int, string> bar = new Pair<int, string>(10, s);
Pair<int, string> qux = new Pair<int, string>(20, s);
Pair<int, int> aaa = ...
How to remove an element from a list by index
...org/projects/python/trunk/Objects/listobject.c how PyList_GetItem() essentially returns ((PyListObject *)op) -> ob_item[i]; - the ith element of an array.
– glglgl
Sep 9 '13 at 7:53
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What is the difference between 'typedef' and 'using' in C++11?
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All standard references below refers to N4659: March 2017 post-Kona working draft/C++17 DIS.
Typedef declarations can, whereas alias declarations cannot, be used as initialization statements
But, with the first two non-temp...
How to do parallel programming in Python?
For C++, we can use OpenMP to do parallel programming; however, OpenMP will not work for Python. What should I do if I want to parallel some parts of my python program?
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Virtual member call in a constructor
I'm getting a warning from ReSharper about a call to a virtual member from my objects constructor.
18 Answers
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Absolute vs relative URLs
...ed Jan 5 '10 at 9:33
Daniel VassalloDaniel Vassallo
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Unique fields that allow nulls in Django
I have model Foo which has field bar. The bar field should be unique, but allow nulls in it, meaning I want to allow more than one record if bar field is null , but if it is not null the values must be unique.
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How can I recover the return value of a function passed to multiprocessing.Process?
... need to know which process is returning which value. If that what you actually need to know about the process, or do you need to correlate between your list of inputs and the list of outputs? In that case, I would recommend using multiprocessing.Pool.map to process your list of work items.
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