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What are some (concrete) use-cases for metaclasses?
...a couple functions I found that I was able to increment the figure count, call draw manually, etc, but I needed to do these before and after every plotting call. So to create both an interactive plotting wrapper and an offscreen plotting wrapper, I found it was more efficient to do this via metacla...
Why is `std::move` named `std::move`?
The C++11 std::move(x) function doesn't really move anything at all. It is just a cast to r-value. Why was this done? Isn't this misleading?
...
How to pretty-print a numpy.array without scientific notation and with given precision?
...335 0.712]
And suppress suppresses the use of scientific notation for small numbers:
y=np.array([1.5e-10,1.5,1500])
print(y)
# [ 1.500e-10 1.500e+00 1.500e+03]
np.set_printoptions(suppress=True)
print(y)
# [ 0. 1.5 1500. ]
See the docs for set_printoptions for other options.
T...
How to add property to a class dynamically?
...ing on. Better late than never.
You can add a property to a class dynamically. But that's the catch: you have to add it to the class.
>>> class Foo(object):
... pass
...
>>> foo = Foo()
>>> foo.a = 3
>>> Foo.b = property(lambda self: self.a + 1)
>>&...
How to make rpm auto install dependencies
...hip and filesystem permissions:
# chown -R root.root /home/user/repo
Install the createrepo package if not installed yet, and run
# createrepo /home/user/repo
# chmod -R o-w+r /home/user/repo
Create a repository configuration file, e.g. /etc/yum.repos.d/myrepo.repo containing
[local]
name=My Aw...
How to invoke the super constructor in Python?
In all other languages I've worked with the super constructor is invoked implicitly. How does one invoke it in Python? I would expect super(self) but this doesn't work.
...
#define macro for debug printing in C?
.... } while (0) idiom ensures that the code acts like a statement (function call). The unconditional use of the code ensures that the compiler always checks that your debug code is valid — but the optimizer will remove the code when DEBUG is 0.
If you want to work with #ifdef DEBUG, then change th...
How do JavaScript closures work?
...clared outside the function, regardless of when and where the function is called.
If a function was called by a function, which in turn was called by another function, then a chain of references to outer lexical environments is created. This chain is called the scope chain.
In the following code, in...
How to give System property to my test via Gradle and -D
...se methods to work. Whatever I do myProperty is always null. This includes all of the methods mentioned below, too. I am wondering if this is something to do with a more recent version, as all comments are from 2018? @CLOVIS did you find a solution to this?
– Hester Lyons
...
In Python, how do I determine if an object is iterable?
...e a method like isiterable ? The only solution I have found so far is to call
21 Answers
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