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Should all Python classes extend object?
...inheritance are different in ways that I won't even try to summarize here. All good documentation that I've seen about MI describes new-style classes.
Finally, old-style classes have disappeared in Python 3, and inheritance from object has become implicit. So, always prefer new style classes unless...
How do you calculate the average of a set of circular data? [closed]
... sum_i_from_1_to_N cos(a[i])
The method given by starblue is computationally equivalent, but his reasons are clearer and probably programmatically more efficient, and also work well in the zero case, so kudos to him.
The subject is now explored in more detail on Wikipedia, and with other uses, l...
Why do we always prefer using parameters in SQL statements?
...uld be
SELECT empSalary from employee where salary = 0 or 1=1
whereby all empSalaries would be returned.
Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee:
SELECT empSalary from employee where salary = 0; Drop Ta...
Why is __dirname not defined in node REPL?
...
Yeah, that should really be added to the answer Eye, because that's what got me.
– Tomáš Zato - Reinstate Monica
Oct 12 '15 at 17:14
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PHP Session Security
...or maintaining responsible session security with PHP? There's information all over the web and it's about time it all landed in one place!
...
String concatenation: concat() vs “+” operator
...then throwing it away when you create the final String. In practice memory allocation is surprisingly fast.
Update: As Pawel Adamski notes, performance has changed in more recent HotSpot. javac still produces exactly the same code, but the bytecode compiler cheats. Simple testing entirely fails bec...
How to replace spaces in file names using a bash script
...whole question is about micro-optimizing more or less. Isn't it fun, after all? ;-)
– Michael Krelin - hacker
Apr 26 '10 at 18:33
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How do I change the working directory in Python?
...If the exception is thrown, do not perform any recursive operations, especially destructive ones. They will operate on the old path and not the new one.
Return to your old directory when you're done. This can be done in an exception-safe manner by wrapping your chdir call in a context manager, lik...
Why do we need virtual functions in C++?
... a rat."
So far so good, right? Animals eat generic food, cats eat rats, all without virtual.
Let's change it a little now so that eat() is called via an intermediate function (a trivial function just for this example):
// This can go at the top of the main.cpp file
void func(Animal *xyz) { xyz-...
Are types like uint32, int32, uint64, int64 defined in any stdlib header?
...
This answer is wrong. All of the above are only available if an exact width type of that size (no padding) exists in the implementation. Even if not, however, the types int_leastNN_t and uint_leastNN_t for NN 8, 16, 32, and 64 must always exist. C...