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Why is parenthesis in print voluntary in Python 2.7?
...
In Python 2.x print is actually a special statement and not a function*.
This is also why it can't be used like: lambda x: print x
Note that (expr) does not create a Tuple (it results in expr), but , does. This likely results in the confusion between...
How to copy a row and insert in same table with a autoincrement field in MySQL?
....)
select c1, c2, ...
from your_table
where id = 1
where c1, c2, ... are all the columns except id. If you want to explicitly insert with an id of 2 then include that in your INSERT column list and your SELECT:
insert into your_table (id, c1, c2, ...)
select 2, c1, c2, ...
from your_table
where i...
How to dynamically load a Python class
...hing like this won't work:
__import__('foo.bar.baz.qux')
You'd have to call the above function like so:
my_import('foo.bar.baz.qux')
Or in the case of your example:
klass = my_import('my_package.my_module.my_class')
some_object = klass()
EDIT: I was a bit off on this. What you're basicall...
Is the C# static constructor thread safe?
... {
mutex.WaitOne();
return instance;
}
// Each call to Acquire() requires a call to Release()
public static void Release()
{
mutex.ReleaseMutex();
}
}
share
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How do I get the opposite (negation) of a Boolean in Python?
...ful if you want to use a function that requires a predicate-function or a callback.
For example map or filter:
>>> lst = [True, False, True, False]
>>> list(map(operator.not_, lst))
[False, True, False, True]
>>> lst = [True, False, True, False]
>>> list(filter...
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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廉价共享存储解决方案2-drbd+cman+gfs2 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...aliyun.com/repo/Centos-6.repo
把$releasever 全部改为6
yum clean all&yum makecache
3、安装DRBD 请参考
http://user.qzone.qq.com/58740020/blog/1448855653
3.1、不一样的地方
同步以上操作或文件,并初始化资源及启动服务
drbdadm create-md r0
service d...
Adding a new value to an existing ENUM Type
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It's worth mentioning that this can all be done in a single transaction, so it's mostly safe to do it in a production database.
– David Leppik
Jul 8 '11 at 20:41
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How can I wait for a thread to finish with .NET?
I've never really used threading before in C# where I need to have two threads, as well as the main UI thread. Basically, I have the following.
...
When to use volatile with multi threading?
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Short & quick answer: volatile is (nearly) useless for platform-agnostic, multithreaded application programming. It does not provide any synchronization, it does not create memory fences, nor does it ensure the order of execut...