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Create a “with” block on several context managers? [duplicate]
...rite:
with A() as X, B() as Y, C() as Z:
do_something()
This is normally the best method to use, but if you have an unknown-length list of context managers you'll need one of the below methods.
In Python 3.3, you can enter an unknown-length list of context managers by using contextlib.Exit...
How assignment works with Python list slice?
...
To be clear, "takes a slice of" really means "make a copy of a slice of" which is where part of the confusion comes from.
– Mark Ransom
May 16 '12 at 17:12
...
Print multiple arguments in Python
...or", name, "is", score)
If you don't want spaces to be inserted automatically by print in the above example, change the sep parameter:
print("Total score for ", name, " is ", score, sep='')
If you're using Python 2, won't be able to use the last two because print isn't a function in Python 2. Y...
Deadly CORS when http://localhost is the origin
...lija's comment is correct, adding these headers to localhost will not magically give you access to all other sites. It's the remote site that needs to be served with these headers.
– Rob W
Mar 22 '14 at 22:59
...
MongoDB vs. Cassandra [closed]
...rly scalable (amortized constant time reads & writes) dynamo/google bigtable hybrid that features fast writes regardless of data size. It's feature set is minimalistic, little beyond that of an ordered key value store. MongoDB is a heavily featured (and fast) document store at the cost of durabi...
Is there a foreach loop in Go?
...pec#For_range
A "for" statement with a "range" clause iterates through all entries
of an array, slice, string or map, or values received on a channel.
For each entry it assigns iteration values to corresponding iteration
variables and then executes the block.
As an example:
for index, e...
Coalesce function for PHP?
...HP 7 introduced a real coalesce operator:
echo $_GET['doesNotExist'] ?? 'fallback'; // prints 'fallback'
If the value before the ?? does not exists or is null the value after the ?? is taken.
The improvement over the mentioned ?: operator is, that the ?? also handles undefined variables without...
What are deferred objects?
...As of jQuery 1.5, the Deferred object provides a way to register multiple callbacks into self-managed callback queues, invoke callback queues as appropriate, and relay the success or failure state of any synchronous or asynchronous function.
Deferred Methods:
deferred.done()
Add handlers to be cal...
Why is it impossible to override a getter-only property and add a setter? [closed]
Why is the following C# code not allowed:
16 Answers
16
...
How to redirect to a 404 in Rails?
...ou want to show a 404 page, create a render_404 method (or not_found as I called it) in ApplicationController like this:
def not_found
raise ActionController::RoutingError.new('Not Found')
end
Rails also handles AbstractController::ActionNotFound, and ActiveRecord::RecordNotFound the same way....