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Read only the first line of a file?
...od (Python 2 docs, Python 3 docs):
with open('myfile.txt') as f:
first_line = f.readline()
Some notes:
As noted in the docs, unless it is the only line in the file, the string returned from f.readline() will contain a trailing newline. You may wish to use f.readline().strip() instead to rem...
Swift - Convert to absolute value
...alue.magnitude) // prints: 5
#2. Get absolute value of an Int from abs(_:) method
Swift has a global numeric function called abs(_:) method. abs(_:) has the following declaration:
func abs<T>(_ x: T) -> T where T : Comparable, T : SignedNumeric
Returns the absolute value of the g...
Android Fragment lifecycle over orientation changes
...mit();
} else {
// do nothing - fragment is recreated automatically
}
Be warned though: problems will occur if you try and access Activity Views from inside the Fragment as the lifecycles will subtly change. (Getting Views from a parent Activity from a Fragment isn't easy).
...
Dependent DLL is not getting copied to the build output folder in Visual Studio
...
@MikeK Adding it to the main project (which doesn't actually directly depend on it) is an even bigger hack, imo. Then you have to manage it two places ("manage" as in upgrade or remove). With this hack, at least you get a nice compile time error reminding you to remove this hack w...
Spring Test & Security: How to mock authentication?
...e properly secured. Just in case someone changes things around and accidentally removes security settings.
7 Answers
...
test if event handler is bound to an element in jQuery [duplicate]
...a('events') has been removed in jQuery 1.8. For "debugging, you can use $._data(element, 'events'), but it's undocumented (and may change). blog.jquery.com/2012/08/09/jquery-1-8-released
– Rocket Hazmat
Aug 16 '12 at 18:43
...
Is it a good practice to use try-except-else in Python?
...o, the use of exceptions in Python does not slow the surrounding code and calling code as it does in some compiled languages (i.e. CPython already implements code for exception checking at every step, regardless of whether you actually use exceptions or not).
In other words, your understanding that...
How is pattern matching in Scala implemented at the bytecode level?
...atterns like or patterns and combinations like "case Foo(45, x)", but generally those are just logical extensions of what I just described. Patterns can also have guards, which are additional constraints on the predicates. There are also cases where the compiler can optimize pattern matching, e.g...
How to get a subset of a javascript object's properties
...og(picked); // { a: 5, c: 7 }
From Philipp Kewisch:
This is really just an anonymous function being called instantly. All of this can be found on the Destructuring Assignment page on MDN. Here is an expanded form
let unwrap = ({a, c}) => ({a, c});
let unwrap2 = function({a, ...
What should I set JAVA_HOME environment variable on macOS X 10.6?
...a_home)
I haven't experienced any problems with that technique.
Occasionally I do have to change the value of JAVA_HOME to an earlier version of Java. For example, one program I'm maintaining requires 32-bit Java 5 on OS X, so when using that program, I set JAVA_HOME by running:
export JAVA_HOM...