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Abstract methods in Python [duplicate]
...to reach method implementations in an ABC, not that you need to use abc in order to use super(). super() works with any new-style class.
– kindall
Sep 20 '17 at 18:41
...
Line continuation for list comprehensions or generator expressions in python
...space follows it). I think it's much better to use it than not, though, in order to keep your line lengths down.
Since \ isn't necessary in the above case, or for parenthesized expressions, I actually find it fairly rare that I even need to use it.
...
Is there a standard sign function (signum, sgn) in C/C++?
...les, unsigned shorts, or any custom types constructible from integer 0 and orderable.
Fast! copysign is slow, especially if you need to promote and then narrow again. This is branchless and optimizes excellently
Standards-compliant! The bitshift hack is neat, but only works for some bit representati...
Pattern to avoid nested try catch blocks?
... of performing a calculation, each of which can fail with an exception. In order to attempt each calculation until we find one that succeeds, I have been doing the following:
...
Creating multiline strings in JavaScript
... @MattBrowne Google's recommendation is already documented by them, in order of importance of reasons: (1) The whitespace at the beginning of each line [in the example, you don't want that whitespace in your string but it looks nicer in the code] (2) whitespace after the slash will result in tri...
Why am I getting an OPTIONS request instead of a GET request?
...d an HTTP OPTIONS request header to the resource on the other
domain, in order to determine whether the actual request is safe to
send. Cross-site requests are preflighted like this since they may
have implications to user data. In particular, a request is
preflighted if:
It uses m...
How to represent multiple conditions in a shell if statement?
... else statement and have the code between then and fi put in a function in order to avoid repeating it. In very simple cases you could use a case statement with ;& fallthrough (in Bash 4).
– Paused until further notice.
Dec 11 '15 at 22:15
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Create an empty data.frame
... Nice solution, however I found that I get a data frame with 0 rows. In order to keep the size of the data frame the same, I suggest new_df = df[NA,]. This also allows to store any previous column into the new data frame. For example to obtain the "Date" column from original df (while keeping res...
Embedding DLLs in a compiled executable
...sses and packs the Microsoft .NET Framework executable (EXE, DLL) files in order to make them smaller.
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Detect permission of camera in iOS
...default:
completion?(.unknown)
}
}
}
And then in order to use it you do
AVCaptureDevice.authorizeVideo(completion: { (status) in
//Your work here
})
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