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What is __future__ in Python used for and how/when to use it, and how it works
__future__ frequently appears in Python modules. I do not understand what __future__ is for and how/when to use it even after reading the Python's __future__ doc .
...
PHP: How to send HTTP response code?
...-Code: 404', true, 404);
I recommend the 2nd one. The first does work on all browsers I have tested, but some minor browsers or web crawlers may have a problem with a header line that only contains a colon. The header field name in the 2nd. variant is of course not standardized in any way and coul...
Interfaces — What's the point?
...ntract. A set of public methods any implementing class has to have. Technically, the interface only governs syntax, i.e. what methods are there, what arguments they get and what they return. Usually they encapsulate semantics as well, although that only by documentation.
You can then have differen...
Python: Checking if a 'Dictionary' is empty doesn't seem to work
...; not dct
True
>>>
Thus, your isEmpty function is unnecessary. All you need to do is:
def onMessage(self, socket, message):
if not self.users:
socket.send("Nobody is online, please use REGISTER command" \
" in order to register into the server")
else:...
Why use apparently meaningless do-while and if-else statements in macros?
...into
if (corge)
f(corge); g(corge);
else
gralt();
which is syntactically incorrect, as the else is no longer associated with the if. It doesn't help to wrap things in curly braces within the macro, because a semicolon after the braces is syntactically incorrect.
if (corge)
{f(corge); g(co...
How can I delete all Git branches which have been merged?
...anches which have already been merged? Is there an easy way to delete them all instead of deleting them one by one?
45 Answ...
How to hash some string with sha256 in Java?
...
SHA-256 isn't an "encoding" - it's a one-way hash.
You'd basically convert the string into bytes (e.g. using text.getBytes(StandardCharsets.UTF_8)) and then hash the bytes. Note that the result of the hash would also be arbitrary binary data, and if you want to represent that in a strin...
What's the recommended approach to resetting migration history using Django South?
...inted out by @thnee below. Since your
answer has so many upvotes I'd really appreciate it if you could edit
it and add at least a warning about this, or (even better) change it
to reflect @hobs approach (which is just as convenient, but doesn't
affect other apps) - thanks! – chris...
How to upload, display and save images using node.js and express [closed]
...
First of all, you should make an HTML form containing a file input element. You also need to set the form's enctype attribute to multipart/form-data:
<form method="post" enctype="multipart/form-data" action="/upload">
<in...
What is the relative performance difference of if/else versus switch statement in Java?
...ic interface Action {
void execute(String input);
}
And get hold of all implementations in some Map. You can do this either statically or dynamically:
Map<String, Action> actions = new HashMap<String, Action>();
Finally replace the if/else or switch by something like this (leav...