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GET URL parameter in PHP
...perglobal: a built-in variable that's populated by PHP and is available in all scopes (you can use it from inside a function without the global keyword).
Since the variable might not exist, you could (and should) ensure your code does not trigger notices with:
<?php
if (isset($_GET['link'])) {
...
What are “first class” objects?
...as
any other object.
A first class object is an entity that can be dynamically created, destroyed, passed to a function, returned as a value, and have all the rights as other variables in the programming language have.
Depending on the language, this can
imply:
being expressible as ...
Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
Why is my git repository so big?
...he whole directory structure.
Edit: Here's Ian's one liner for recreating all branches in the new repo:
d1=#original repo
d2=#new repo (must already exist)
cd $d1
for b in $(git branch | cut -c 3-)
do
git checkout $b
x=$(git rev-parse HEAD)
cd $d2
git checkout -b $b $x
cd $d1
d...
How does functools partial do what it does?
...xtend(extra_args)
return func(*args)
return wrapper
So, by calling partial(sum2, 4) you create a new function (a callable, to be precise) that behaves like sum2, but has one positional argument less. That missing argument is always substituted by 4, so that partial(sum2, 4)(2) == sum2...
multiprocessing.Pool: When to use apply, apply_async or map?
...
Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:
apply(f,args,kwargs)
apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,
f(*args,**kwargs)
is preferred. The...
Is there a range class in C++11 for use with range based for loops?
...:irange, which is a bit more focused in scope.
C++20's range library will allow you to do this via view::iota(start, end).
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Error handling in Bash
...kens code's predictability and portability).
You can either let the trap call error for you (in which case it uses the default exit code of 1 and no message) or call it yourself and provide explicit values; for instance:
error ${LINENO} "the foobar failed" 2
will exit with status 2, and give an ...
How can I use PowerShell with the Visual Studio Command Prompt?
...
Stealing liberally from here: http://allen-mack.blogspot.com/2008/03/replace-visual-studio-command-prompt.html, I was able to get this to work. I added the following to my profile.ps1 and all is well with the world.
pushd 'c:\Program Fil...
std::enable_if to conditionally compile a member function
... I want to use std::enable_if to choose between two member-functions and allow only one of them to be used.
7 Answers
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