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C-like structures in Python
...uct(NamedTuple):
foo: str
bar: int
baz: list
qux: User
my_item = MyStruct('foo', 0, ['baz'], User('peter'))
print(my_item) # MyStruct(foo='foo', bar=0, baz=['baz'], qux=User(name='peter'))
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Why are floating point numbers inaccurate?
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Seeing the Data
First, a few functions to see the components that make a 32- and 64-bit float. Gloss over these if you only care about the output (example in Python):
def float_to_bin_parts(number, bits=64):
if bits == 32: # single precision
int_pack = 'I'
float_...
Initialize class fields in constructor or at declaration?
...
kokoskokos
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How do I inspect the view hierarchy in iOS?
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I've got: error: cannot find interface declaration for '$__lldb_objc_class' any ideas? (lldb) po [[UIWindow keyWindow] recursiveDescription] error: cannot find interface declaration for '$__lldb_objc_class' error: cannot find interface declaration for '$__lldb_objc_class' error:...
JPA and Hibernate - Criteria vs. JPQL or HQL
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32
HQL is much easier to read, easier to debug using tools like the Eclipse Hibernate plugin, and ...
ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.al
...rrays causes the two arrays to be evaluated in boolean context (by
calling __bool__ in Python3 or __nonzero__ in Python2).
Your original code
mask = ((r["dt"] >= startdate) & (r["dt"] <= enddate))
selected = r[mask]
looks correct. However, if you do want and, then instead of a and b u...
Cloning an Object in Node.js
...ion is now marked as deprecated in the documentation of Node.js:
The util._extend() method was never intended to be used outside of internal Node.js modules. The community found and used it anyway.
It is deprecated and should not be used in new code. JavaScript comes with very similar built-in func...
Can media queries resize based on a div element instead of the screen?
I would like to use media queries to resize elements based on the size of a div element they are in. I cannot use the screen size as the div is just used like a widget within the webpage, and its size can vary.
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ReactJS - Does render get called any time “setState” is called?
Does React re-render all components and sub components every time setState() is called?
7 Answers
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Iterating C++ vector from the end to the beginning
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The best way is:
for (vector<my_class>::reverse_iterator i = my_vector.rbegin();
i != my_vector.rend(); ++i ) {
}
rbegin()/rend() were especially designed for that purpose. (And yes, incrementing a reverse_interator moves it backward.)
Now...