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How to explain callbacks in plain english? How are they different from calling one function from ano
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Often an application needs to execute different functions based upon its context/state. For this, we use a variable where we would store the information about the function to be called. According to its need the application will set this variable with the information about function to be ca...
pip installing in global site-packages instead of virtualenv
...ackage in a virtualenv causes the package to be installed in the global site-packages folder instead of the one in the virtualenv folder. Here's how I set up Python3 and virtualenv on OS X Mavericks (10.9.1):
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When is layoutSubviews called?
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I had a similar question, but wasn't satisfied with the answer (or any I could find on the net), so I tried it in practice and here is what I got:
init does not cause layoutSubviews to
be called (duh)
addSubview: causes
layoutSubviews to be called on the
view being adde...
“is” operator behaves unexpectedly with integers
...ere's what I found in the Python 2 documentation, "Plain Integer Objects" (It's the same for Python 3):
The current implementation keeps an
array of integer objects for all
integers between -5 and 256, when you
create an int in that range you
actually just get back a reference to
the e...
Command line to remove an environment variable from the OS level configuration
...e variable from the user environment (which is the default place setx puts it):
REG delete HKCU\Environment /F /V FOOBAR
If the variable is set in the system environment (e.g. if you originally set it with setx /M), as an administrator run:
REG delete "HKLM\SYSTEM\CurrentControlSet\Control\Sessi...
Why is #!/usr/bin/env bash superior to #!/bin/bash?
I've seen in a number of places, including recommendations on this site ( What is the preferred Bash shebang? ), to use #!/usr/bin/env bash in preference to #!/bin/bash . I've even seen one enterprising individual suggest using #!/bin/bash was wrong and bash functionality would be lost by doing...
How can I break up this long line in Python?
...ow would you go about formatting a long line such as this? I'd like to get it to no more than 80 characters wide:
5 Answers...
What is the use of the ArraySegment class?
...egment<T> has become a lot more useful in .NET 4.5+ and .NET Core as it now implements:
IList<T>
ICollection<T>
IEnumerable<T>
IEnumerable
IReadOnlyList<T>
IReadOnlyCollection<T>
as opposed to the .NET 4 version which implemented no interfaces whatsoever.
The...
How to unset a JavaScript variable?
...al variable in JavaScript (actually a window property, but I don't think it matters) which was already populated by a previous script but I don't want another script that will run later to see its value or that it was even defined.
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How to properly override clone method?
...h Bloch on Design - Copy Constructor versus Cloning
If you've read the item about cloning in my book, especially if you read between the lines, you will know that I think clone is deeply broken. [...] It's a shame that Cloneable is broken, but it happens.
You may read more discussion on the to...