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Comma in C/C++ macro
...his is also a problem for square brackets and braces, even though those usually occur as balanced pairs.) You can enclose the macro argument in parentheses:
FOO((std::map<int, int>), map_var);
The problem is then that the parameter remains parenthesized inside the macro expansion, which pr...
Cleanest way to get last item from Python iterator
...specific default value could even be correct? If the iterator doesn't actually iterate, then an out-of-band value is more meaningful than some misleading function-specific default.
– S.Lott
Jan 26 '10 at 11:44
...
Get all related Django model objects
How can I get a list of all the model objects that have a ForeignKey pointing to an object? (Something like the delete confirmation page in the Django admin before DELETE CASCADE).
...
Why does += behave unexpectedly on lists?
...
The general answer is that += tries to call the __iadd__ special method, and if that isn't available it tries to use __add__ instead. So the issue is with the difference between these special methods.
The __iadd__ special method is for an in-place addition, that i...
Is there a generator version of `string.split()` in Python?
...plitlines chops off the trainling newline though (something that I don't really like...); if you wanted to replicated that part of the behavior, you could use grouping: (m.group(2) or m.group(3) for m in re.finditer('((.*)\n|(.+)$)', s)). PS: I guess the outer paren in the RE are not needed; I just ...
C# Sortable collection which allows duplicate keys
... Use this Comparer e.g. with SortedLists or SortedDictionaries, that don't allow duplicate keys
/// </summary>
/// <typeparam name="TKey"></typeparam>
public class DuplicateKeyComparer<TKey>
:
IComparer<TKey> where TKey : IComparable
{
#...
How does JavaScript .prototype work?
...ing languages but I've written my fair share of JavaScript code. I never really got my head around this prototype-based programming, does any one know how this works?
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Django rest framework nested self-referential objects
... the `subcategories` field
return CategorySerializer()
Actually, as you've noted the above isn't quite right.
This is a bit of a hack, but you might try adding the field in after the serializer is already declared.
class CategorySerializer(serializers.ModelSerializer):
parentCat...
How can I multiply and divide using only bit shifting and adding?
...kes a constant multiple of time compared to addition and shifting. If I recall correctly, modern processors, if pipelined properly, can do multiplication just about as fast as addition, by messing with the utilization of the ALUs (arithmetic units) in the processor.
...
When do we need curly braces around shell variables?
...xpand the variable identified by foobar.
Curly braces are also unconditionally required when:
expanding array elements, as in ${array[42]}
using parameter expansion operations, as in ${filename%.*} (remove extension)
expanding positional parameters beyond 9: "$8 $9 ${10} ${11}"
Doing this every...