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What's the point of malloc(0)?
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According to the specifications, malloc(0) will return either "a null pointer or a unique pointer that can be successfully passed to free()".
This basically lets you allocate nothing, but still pass the "artist" variable to a call to free() without worry. For practical purposes,...
Numpy - add row to array
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What is X? If it is a 2D-array, how can you then compare its row to a number: i < 3?
EDIT after OP's comment:
A = array([[0, 1, 2], [0, 2, 0]])
X = array([[0, 1, 2], [1, 2, 0], [2, 1, 2], [3, 2, 0]])
add to A all rows from X where t...
Get top n records for each group of grouped results
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Here is one way to do this, using UNION ALL (See SQL Fiddle with Demo). This works with two groups, if you have more than two groups, then you would need to specify the group number and add queries for each group:
(
select *
from mytable
where `group` = 1
order by age desc
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What's the reason I can't create generic array types in Java?
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It's because Java's arrays (unlike generics) contain, at runtime, information about its component type. So you must know the component type when you create the array. Since you don't know what T is at runtime, you can't creat...
Set size on background image with CSS?
Is it possible to set the size of the background image with CSS?
18 Answers
18
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How to remove/ignore :hover css style on touch devices
I want to ignore all :hover CSS declarations if a user visits our website via touch device. Because the :hover CSS does not make sense, and it can even be disturbing if a tablet triggers it on click/tap because then it might stick until the element loses focus. To be honest, I don't know why tou...
How do I pass a string into subprocess.Popen (using the stdin argument)?
...nd data to
the process’s stdin, you need to
create the Popen object with
stdin=PIPE. Similarly, to get anything
other than None in the result tuple,
you need to give stdout=PIPE and/or
stderr=PIPE too.
Replacing os.popen*
pipe = os.popen(cmd, 'w', bufsize)
# ==>
p...
Chained method calls indentation style in Python [duplicate]
From reading PEP-8, I get it that you should put the closing parenthesis on the same line as the last argument in function calls:
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How can I test what my readme.md file will look like before committing to github?
I am writing a readme for my github project in the .md format. Is there a way can I test what my readme.md file will look like before committing to github?
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Java Class.cast() vs. cast operator
...lt;T> T doSomething() {
Object o;
// snip
return (T) o;
}
It's often best to replace it by:
<T> T doSomething(Class<T> cls) {
Object o;
// snip
return cls.cast(o);
}
That's the only use case for Class.cast(Object) I've ever come across.
Regarding compiler...