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Setting an environment variable before a command in Bash is not working for the second command in a
In a given shell, normally I'd set a variable or variables and then run a command. Recently I learned about the concept of prepending a variable definition to a command:
...
String comparison in Python: is vs. == [duplicate]
...
For all built-in Python objects (like
strings, lists, dicts, functions,
etc.), if x is y, then x==y is also
True.
Not always. NaN is a counterexample. But usually, identity (is) implies equality (==). The converse is n...
What does the Reflect object do in JavaScript?
...ble:
ES6 spec, Reflection
MDN Reflect (including details and examples to all of its methods)
Original answer (for (historic) understanding and extra examples):
The Reflection proposal seems to have progressed to the Draft ECMAScript 6 Specification. This document currently outlines the Reflect...
Creating functions in a loop
...have a function that accesses a global variable, like this:
global_var = 'foo'
def my_function():
print(global_var)
global_var = 'bar'
my_function()
When you read this code, you would - of course - expect it to print "bar", not "foo", because the value of global_var has changed after the fu...
Python Remove last 3 characters of a string
...
Removing any and all whitespace:
foo = ''.join(foo.split())
Removing last three characters:
foo = foo[:-3]
Converting to capital letters:
foo = foo.upper()
All of that code in one line:
foo = ''.join(foo.split())[:-3].upper()
...
How to test if list element exists?
...
This is actually a bit trickier than you'd think. Since a list can actually (with some effort) contain NULL elements, it might not be enough to check is.null(foo$a). A more stringent test might be to check that the name is actually defin...
If Python is interpreted, what are .pyc files?
...'translated'. Python is then compiled to a bytecode. AFAIK, only Bash is really interpreted , all other popular "interpreted" languages are all compiled to a bytecode.
– bfontaine
Aug 6 '14 at 13:42
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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...
Hidden Features of Java
...en I first discovered it, never heard of it before.
ThreadLocals are typically not so widely known as a way to store per-thread state.
Since JDK 1.5 Java has had extremely well implemented and robust concurrency tools beyond just locks, they live in java.util.concurrent and a specifically interest...
How to get started with developing Internet Explorer extensions?
...er the BHO (needs registry access).
Start by creating a class library.
I called mine InternetExplorerExtension.
Add these references to the project:
Interop.SHDocVw: COM tab / search for "Microsoft Internet Controls"
Microsoft.mshtml: Assemblies tab / search for "Microsoft.mshtml"
Note: Someho...