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What is __future__ in Python used for and how/when to use it, and how it works
...division ("true division") and others return the floor ("floor division"). Starting in Python 3.0, true division is specified by x/y, whereas floor division is specified by x//y.
The from __future__ import division directive forces the use of Python 3.0 style division.
absolute_import
Allows for...
Is String.Format as efficient as StringBuilder
...em.Diagnostics.Stopwatch();
Console.WriteLine("Concatenation:");
stopwatch.Start();
for(int i=0; i<iterations; i++){
var key1= keyprefix+":" + i.ToString();
concatkeys[i]=key1;
}
Console.WriteLine(stopwatch.ElapsedMilliseconds);
Console.WriteLine("New stringBuilder for each key:");
sto...
What's the best practice for primary keys in tables?
...ho hasn't supplied his/her SSN yet.
Employee Salary History: (employee_id, start_date). I would not create an artifical employee_salary_history_id. What point would it serve (other than "foolish consistency")
Wherever artificial keys are used, you should always also declare unique constraints on...
Unicode, UTF, ASCII, ANSI format differences
...
Some reading to get you started on character encodings: Joel on Software:
The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!)
By the way - ASP.NET has nothing to do with it....
Java 理论与实践: 线程池与工作队列 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...i++) {
threads[i] = new PoolWorker();
threads[i].start();
}
}
public void execute(Runnable r) {
synchronized(queue) {
queue.addLast(r);
queue.notify();
}
}
private class PoolWorker extends Thread {
...
How does virtual inheritance solve the “diamond” (multiple inheritance) ambiguity?
...helped me to wrap head around virtual inheritance.
Double A
First, lets start with this code without virtual inheritance:
#include<iostream>
using namespace std;
class A {
public:
A() { cout << "A::A() "; }
A(int x) : m_x(x) { cout << "A::A(" << x ...
What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function
... always be a string
Not only contain digits, ASCII letters and underscores
Start with an integer (dict(1foo=2) raises a SyntaxError)
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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...
There are many ways to do this. This answer starts with what is quickly becoming the standard method, but also includes older methods and various other methods from answers to similar questions scattered around this site.
tmp <- data.frame(x=gl(2,3, labels=letters[...
Tool to convert Python code to be PEP8 compliant
...n several big companies. Was created later than yapf, but already has more starts at GitHub
yapf https://github.com/google/yapf Google code formatter
autopep8 https://github.com/hhatto/autopep8 build upon the
pycodestyle
sh...
Avoid web.config inheritance in child web application using inheritInChildApplications
...e in the connection string. This made the string unique and all of sudden started to fail.
Without doing any research on the exact reason for this, I have to assume that when the child application inherits the parents web.config values, it ignores identical key/value pairs.
We were able to solve ...