大约有 40,000 项符合查询结果（耗时：0.0719秒） [XML]
Rename a dictionary key
... this question seems to be asking, is impractical because dict keys are usually immutable objects such as numbers, strings or tuples. Instead of trying to modify the key, reassigning the value to a new key and removing the old key is how you can achieve the "rename" in python.
...
How to activate virtualenv?
... virtualenv venv --distribute
New python executable in venv/bin/python
Installing distribute.........done.
Installing pip................done.
$ source venv/bin/activate
(venv)$ python
share
|
impr...
How to send a PUT/DELETE request in jQuery?
...ch as PUT and DELETE, can also be used here, but they are not supported by all browsers." from: api.jquery.com/jQuery.ajax/#options
– andilabs
Dec 2 '13 at 8:11
23
...
Make the current commit the only (initial) commit in a Git repository?
...e using submodules, you should use e.g. interactive rebase
Step 1: remove all history (Make sure you have backup, this cannot be reverted)
cat .git/config # note <github-uri>
rm -rf .git
Step 2: reconstruct the Git repo with only the current content
git init
git add .
git commit -m "Init...
Python Pandas: Get index of rows which column matches certain value
... frame (whose data may be gibabytes). What about dftest? Doesn't this also allocate a very large intermediate object where the returned index may be very small, or even empty. Are these magically optimized away using lazy views. If not then surely there must be an efficient way.
...
How would one write object-oriented code in C? [closed]
What are some ways to write object-oriented code in C? Especially with regard to polymorphism.
32 Answers
...
What is lexical scope?
...
I understand them through examples. :)
First, lexical scope (also called static scope), in C-like syntax:
void fun()
{
int x = 5;
void fun2()
{
printf("%d", x);
}
}
Every inner level can access its outer levels.
There is another way, called dynamic scope used by ...
How do I set a cookie on HttpClient's HttpRequestMessage
...instantiated once and re-used throughout the life of an application. Especially in server applications, creating a new HttpClient instance for every request will exhaust the number of sockets available under heavy loads..." From here: asp.net/web-api/overview/advanced/…
– Ser...
What is DOM Event delegation?
...ame effect.
So what's the benefit?
Imagine you now have a need to dynamically add new <li> items to the above list via DOM manipulation:
var newLi = document.createElement('li');
newLi.innerHTML = 'Four';
myUL.appendChild(newLi);
Without using event delegation you would have to "rebind" t...
How to define “type disjunction” (union types)?
...str")
case _: Int => println("int")
}
}
And that's it. You can call foo(5) or foo("abc"), and it will work, but try foo(true) and it will fail. This could be side-stepped by the client code by creating a StringOrInt[Boolean], unless, as noted by Randall below, you make StringOrInt a seale...