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What does the “yield” keyword do?
... list, you can read its items one by one. Reading its items one by one is called iteration:
>>> mylist = [1, 2, 3]
>>> for i in mylist:
... print(i)
1
2
3
mylist is an iterable. When you use a list comprehension, you create a list, and so an iterable:
>>> mylist = [...
Usage of __slots__?
What is the purpose of __slots__ in Python — especially with respect to when I would want to use it, and when not?
11 A...
How do I control how Emacs makes backup files?
...tory as the file you're editing,
but that is easy to change. You can make all backup files go
into a directory by putting something like the following in your
.emacs.
(setq backup-directory-alist `(("." . "~/.saves")))
There are a number of arcane details associated with how Emacs
might create y...
How can I remove a trailing newline?
...; 'test string\n'.rstrip()
'test string'
Python's rstrip() method strips all kinds of trailing whitespace by default, not just one newline as Perl does with chomp.
>>> 'test string \n \r\n\n\r \n\n'.rstrip()
'test string'
To strip only newlines:
>>> 'test string \n \r\n\n\r \...
IntelliJ and Tomcat.. Howto..?
...ites with Tomcat as the local server to manage it.
In Netbeans it was "Install, write hit Run and it works"
How do I pull the same thing off in IntelliJ?
...
Similar to jQuery .closest() but traversing descendants?
...found.length) break; // At least one match: break loop
// Get all children of the current set
$currentSet = $currentSet.children();
}
return $found.first(); // Return first match of the collection
}
})(jQuery);
...
What is “stdafx.h” used for in Visual Studio?
A file named stdafx.h is automatically generated when I start a project in Visual Studio 2010. I need to make a cross-platform C++ library, so I don't/can't use this header file.
...
What is an “unwrapped value” in Swift?
...st, you have to understand what an Optional type is. An optional type basically means that the variable can be nil.
Example:
var canBeNil : Int? = 4
canBeNil = nil
The question mark indicates the fact that canBeNil can be nil.
This would not work:
var cantBeNil : Int = 4
cantBeNil = nil // can...
How to validate an email address in JavaScript
...b"@gmail.com, _@gmail.com, 1@gmail.com , 1_example@something.gmail.com are all valid, but Gmail will never allow any of these email addresses. You should do this by accepting the email address and sending an email message to that email address, with a code/link the user must visit to confirm validit...
How to succinctly write a formula with many variables from a data frame?
...
There is a special identifier that one can use in a formula to mean all the variables, it is the . identifier.
y <- c(1,4,6)
d <- data.frame(y = y, x1 = c(4,-1,3), x2 = c(3,9,8), x3 = c(4,-4,-2))
mod <- lm(y ~ ., data = d)
You can also do things like this, to use all variables but...