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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...
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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...
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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...
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open read and close a file in 1 line of code

... You don't really have to close it - Python will do it automatically either during garbage collection or at program exit. But as @delnan noted, it's better practice to explicitly close it for various reasons. So, what you can do to keep ...
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Simplest/Cleanest way to implement singleton in JavaScript?

... return { // public interface publicMethod1: function () { // all private members are accessible here }, publicMethod2: function () { } }; })(); This has been called the module pattern, it basically allows you to encapsulate private members on an object, by taking advant...
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Why is my git repository so big?

...he whole directory structure. Edit: Here's Ian's one liner for recreating all branches in the new repo: d1=#original repo d2=#new repo (must already exist) cd $d1 for b in $(git branch | cut -c 3-) do git checkout $b x=$(git rev-parse HEAD) cd $d2 git checkout -b $b $x cd $d1 d...
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How to calculate the bounding box for a given lat/lng location?

... I suggest to approximate locally the Earth surface as a sphere with radius given by the WGS84 ellipsoid at the given latitude. I suspect that the exact computation of latMin and latMax would require elliptic functions and would not yield an appreciable ...
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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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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...
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Python list directory, subdirectory, and files

I'm trying to make a script to list all directory, subdirectory, and files in a given directory. I tried this: 7 Answers ...