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In-memory size of a Python structure
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@AlexMartelli Hi Alex! .. Why minimum size of a char in python is 25 bytes. >>> getsizeof('a') gives 25 and >>> getsizeof('ab') gives 26 `
– Grijesh Chauhan
Jan 17 '13 at 5:13
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How to append rows to an R data frame
...<- function(n){
df <- data.frame(x = numeric(n), y = character(n), stringsAsFactors = FALSE)
for(i in 1:n){
df$x[i] <- i
df$y[i] <- toString(i)
}
df
}
Here's a similar approach, but one where the data.frame is created as the last step.
# Use preallocated vectors
f4 <...
Where to put include statements, header or source?
...def.h> in the header file.
Your function uses strlen. Then #include <string.h> in the source file.
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Changing variable names in Vim
...nvar()
expand("<cword>") gets the word under the cursor. The search string uses % for file-scope, and the \(\W\) patterns look for non-word characters at the boundary of the word to replace, and save them in variables \1 and \2 so as to be re-inserted in the replacement pattern.
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Difference between 'new operator' and 'operator new'?
...ething like your own container, you can call operator new directly, like:
char *x = static_cast<char *>(operator new(100));
It's also possible to overload operator new either globally, or for a specific class. IIRC, the signature is:
void *operator new(size_t);
Of course, if you overloa...
How can I get query string values in JavaScript?
Is there a plugin-less way of retrieving query string values via jQuery (or without)?
73 Answers
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Problem with converting int to string in Linq to entities
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With EF v4 you can use SqlFunctions.StringConvert. There is no overload for int so you need to cast to a double or a decimal. Your code ends up looking like this:
var items = from c in contacts
select new ListItem
{
Va...
What are free monads?
...gives you a way to "get out" of it.
More generally, if X is a Y with some extra stuff P, then a "free X" is a a way of getting from a Y to an X without gaining anything extra.
Examples: a monoid (X) is a set (Y) with extra structure (P) that basically says it has an operation (you can think of add...
What is the advantage to using bloom filters?
... bits, for small integers, to an
arbitrary number of bits, such as for
strings (tries are an exception, since
they can share storage between
elements with equal prefixes). Linked
structures incur an additional linear
space overhead for pointers. A Bloom
filter with 1% error and an opti...
Boolean vs boolean in Java
... Booleans, conditional operators and autoboxing):
public static void main(String[] args) throws Exception {
Boolean b = true ? returnsNull() : false; // NPE on this line.
System.out.println(b);
}
public static Boolean returnsNull() {
return null;
}
Use Boolean when you need an object, e...