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What's a correct and good way to implement __hash__()?
...be integers, and there aren't too many of them, I suppose you could potentially run slightly faster with some home-rolled hash, but it likely wouldn't be as well distributed. hash((self.attr_a, self.attr_b, self.attr_c)) is going to be surprisingly fast (and correct), as creation of small tuples is ...
Ignore python multiple return value
...add gettext functionality to someone else's code (that defines a function called '_') so it should be banned
– nosklo
Jan 11 '09 at 13:32
28
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How can I force division to be floating point? Division keeps rounding down to 0?
... a floating point number in Python in the following?
c = a / b
What is really being asked here is:
"How do I force true division such that a / b will return a fraction?"
Upgrade to Python 3
In Python 3, to get true division, you simply do a / b.
>>> 1/2
0.5
Floor division, the classic di...
Get absolute path of initially run script
...tioning that, reading the documentation, there is no mention that the initially run script's path is the first item of the array returned by get_included_files(). I suggest to store __FILE__ into a constant at the beginning of the script meant to be initially run.
– Paolo
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C++11 reverse range-based for-loop
...
Actually Boost does have such adaptor: boost::adaptors::reverse.
#include <list>
#include <iostream>
#include <boost/range/adaptor/reversed.hpp>
int main()
{
std::list<int> x { 2, 3, 5, 7, 11, 13, 1...
Java: parse int value from a char
...So e.g. '0' in ascii is 48, '1' is 49, etc. So if you take '2' - '0' you really just get 50 - 48 = 2. Have a look at an ASCII table in order to understand this principle better. Also, 'x' means get the ascii value of the character in Java.
– Kevin Van Ryckegem
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How do I get the path of the current executed file in Python?
...ike a newbie question, but it is not. Some common approaches don't work in all cases:
13 Answers
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Catch an exception thrown by an async void method
...ET,
is it possible to catch an exception thrown by an async method in the calling method?
6 Answers
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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...
JRE 1.7 - java version - returns: java/lang/NoClassDefFoundError: java/lang/Object
...
This problem stems from an improper Java installation.
Possibility 1
NOTE: This scenario only applies to Java 8 and prior. Beginning with Java 9, the JRE is structured differently. rt.jar and friends no longer exist, and Pack200 is no longer used.
The Java standa...