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How to run a program without an operating system?

How do you run a program all by itself without an operating system running? Can you create assembly programs that the computer can load and run at startup, e.g. boot the computer from a flash drive and it runs the program that is on the CPU? ...
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Is there a range class in C++11 for use with range based for loops?

...:irange, which is a bit more focused in scope. C++20's range library will allow you to do this via view::iota(start, end). share | improve this answer | follow ...
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What is “:-!!” in C code?

...sizeof(struct { int: -!!(e); })) (e): Compute expression e. !!(e): Logically negate twice: 0 if e == 0; otherwise 1. -!!(e): Numerically negate the expression from step 2: 0 if it was 0; otherwise -1. struct{int: -!!(0);} --> struct{int: 0;}: If it was zero, then we declare a struct with an an...
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Pass a parameter to a fixture function

... through the tester fixture. I had a similar problem--I have a fixture called test_package, and I later wanted to be able to pass an optional argument to that fixture when running it in specific tests. For example: @pytest.fixture() def test_package(request, version='1.0'): ... request....
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Creating JS object with Object.create(null)?

...t.create(null) doesn't inherit from anything and thus has no properties at all. In other words: A javascript object inherits from Object by default, unless you explicitly create it with null as its prototype, like: Object.create(null). {} would instead be equivalent to Object.create(Object.prototy...
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namedtuple and default values for optional keyword arguments

...lds) >>> Node() Node(val=None, left=None, right=None) Order In all versions of Python, if you set fewer default values than exist in the namedtuple, the defaults are applied to the rightmost parameters. This allows you to keep some arguments as required arguments. >>> Node.__ne...
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Efficiently updating database using SQLAlchemy ORM

...ngs in mind when using the ORM and plain SQL in the same transaction. Basically, from one side, ORM data modifications will only hit the database when you flush the changes from your session. From the other side, SQL data manipulation statements don't affect the objects that are in your session. So...
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Reference — What does this symbol mean in PHP?

... have the same results. Pre-increment is a little bit faster because it really increments the variable and after that 'returns' the result. Post-increment creates a special variable, copies there the value of the first variable and only after the first variable is used, replaces its value with seco...
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Is it possible to specify your own distance function using scikit-learn K-Means Clustering?

... Here's a small kmeans that uses any of the 20-odd distances in scipy.spatial.distance, or a user function. Comments would be welcome (this has had only one user so far, not enough); in particular, what are your N, dim, k, metric ? #!/u...
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Compare object instances for equality by their attributes

...s: >>> x == y True Note that implementing __eq__ will automatically make instances of your class unhashable, which means they can't be stored in sets and dicts. If you're not modelling an immutable type (i.e. if the attributes foo and bar may change value within the lifetime of your obje...