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correct way to use super (argument passing)
...
If you're going to have a lot of inheritence (that's the case here) I suggest you to pass all parameters using **kwargs, and then pop them right after you use them (unless you need them in upper classes).
class First(object)...
Accessing Object Memory Address
...ch is guaranteed to be unique and
constant for this object during its
lifetime. Two objects with
non-overlapping lifetimes may have the
same id() value. (Implementation note:
this is the address of the object.)
So in CPython, this will be the address of the object. No such guarantee for ...
What does __FILE__ mean in Ruby?
...preted as "foo.rb".
Edit: Ruby 1.9.2 and 1.9.3 appear to behave a little differently from what Luke Bayes said in his comment. With these files:
# test.rb
puts __FILE__
require './dir2/test.rb'
# dir2/test.rb
puts __FILE__
Running ruby test.rb will output
test.rb
/full/path/to/dir2/test.rb
...
Parse config files, environment, and command-line arguments, to get a single collection of options
...es it so that,
my_prog --foo=bar
is equivalent to
my_prog @baz.conf
if @baz.conf is,
--foo
bar
You can even have your code look for foo.conf automatically by modifying argv
if os.path.exists('foo.conf'):
argv = ['@foo.conf'] + argv
args = argparser.parse_args(argv)
The format of the...
How to make an unaware datetime timezone aware in python
...15, 12, 0)
aware = datetime.datetime(2011, 8, 15, 8, 15, 12, 0, pytz.UTC)
now_aware = pytz.utc.localize(unaware)
assert aware == now_aware
For the UTC timezone, it is not really necessary to use localize since there is no daylight savings time calculation to handle:
now_aware = unaware.replace(t...
Entity Framework with NOLOCK
...
@FMFF I don't know if anything new was introduced for EF4. I do know that the above code works with EFv1 and above though.
– Doctor Jones
Feb 28 '12 at 16:08
...
File Upload ASP.NET MVC 3.0
... public ActionResult Index(HttpPostedFileBase file)
{
// Verify that the user selected a file
if (file != null && file.ContentLength > 0)
{
// extract only the filename
var fileName = Path.GetFileName(file.FileName);
// s...
C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
...ount *Ref() {
++cnt_;
return this;
}
void Deref() {
if (--cnt_ == 0) {
delete this;
}
}
private:
std::unique_ptr<T> ptr_;
std::atomic_uint32_t cnt_;
};
仔细观察可以发现：
每一次的读取操作对应引用计数中增加的数值 1；
...
How to check if the string is empty?
... they are considered false in a Boolean context, so you can just do this:
if not myString:
This is the preferred way if you know that your variable is a string. If your variable could also be some other type then you should use myString == "". See the documentation on Truth Value Testing for ot...
List all the files that ever existed in a Git repository
Do you have a clean way to list all the files that ever existed in specified branch?
4 Answers
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