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How can I pad an integer with zeros on the left?
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If you have to do this for a large list of values, performance of DecimalFormat is at least 3 times better than String.format(). I'm in the process of doing some performance tuning myself and running the two in Visual VM sho...
Create a “with” block on several context managers? [duplicate]
...() as Z:
do_something()
This is normally the best method to use, but if you have an unknown-length list of context managers you'll need one of the below methods.
In Python 3.3, you can enter an unknown-length list of context managers by using contextlib.ExitStack:
with ExitStack() as stack...
Problems with entering Git commit message with Vim
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If it is VIM for Windows, you can do the following:
enter your message following the presented guidelines
press Esc to make sure you are out of the insert mode
then type :wqEnter or ZZ.
Note that in VIM there are often se...
On localhost, how do I pick a free port number?
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Do not bind to a specific port, or bind to port 0, e.g. sock.bind(('', 0)). The OS will then pick an available port for you. You can get the port that was chosen using sock.getsockname()[1], and pass it on to the slaves so that they can connect...
Constructor overloading in Java - best practice
...2) {
// Guard statements, initialize resources or throw exceptions if
// the resources are wrong
if (r1 == null) {
r1 = new Resource();
}
if (r2 == null) {
r2 = new Resource();
}
// do whatever with resources
}
}
...
Are lists thread-safe?
...r example:
L[0] += 1
is not guaranteed to actually increase L[0] by one if another thread does the same thing, because += is not an atomic operation. (Very, very few operations in Python are actually atomic, because most of them can cause arbitrary Python code to be called.) You should use Queues...
How to get back to most recent version in Git?
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When you checkout to a specific commit, git creates a detached branch. So, if you call:
$ git branch
You will see something like:
* (detached from 3i4j25)
master
other_branch
To come back to the master branch head you just need to checkout ...
How to 'grep' a continuous stream?
...(on Ubuntu 14.04, GNU grep version 2.16). Where is the "use line buffering if stdout is a tty" logic implemented? In git.savannah.gnu.org/cgit/grep.git/tree/src/grep.c, line_buffered is set only by the argument parser.
– Aasmund Eldhuset
Jan 9 '17 at 22:21
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Convert integer into byte array (Java)
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this would work well if the bytebuffer is already there... otherwise it seems like it would take longer to do the allocation, than to just allocate a byte array of length 4 and do the shifting manually... but we're probably talking about small di...
How to initialize const member variable in a class?
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The const variable specifies whether a variable is modifiable or not. The constant value assigned will be used each time the variable is referenced. The value assigned cannot be modified during program execution.
Bjarne Stroustrup's explanation su...