大约有 47,000 项符合查询结果（耗时：0.0515秒） [XML]
[] and {} vs list() and dict(), which is better?
...gt;> from timeit import timeit
>>> timeit("[]")
0.040084982867934334
>>> timeit("list()")
0.17704233359267718
>>> timeit("{}")
0.033620194745424214
>>> timeit("dict()")
0.1821558326547077
and for non-empty:
>>> timeit("[1,2,3]")
0.24316302770330367
...
Maven dependency for Servlet 3.0 API?
How can I tell Maven 2 to load the Servlet 3.0 API?
10 Answers
10
...
Regular expression to match standard 10 digit phone number
...
^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
Matches the following
123-456-7890
(123) 456-7890
123 456 7890
123.456.7890
+91 (123) 456-7890
If you do not want a match on non-US numbers use
^(\+0?1\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
...
Centering the pagination in bootstrap
...
Bootstrap has added a new class from 3.0.
<div class="text-center">
<ul class="pagination">
<li><a href="?p=0" data-original-title="" title="">1</a></li>
<li><a href="?p=1" data-original-title=""...
Removing duplicates in lists
...ample should cover whatever you are trying to do:
>>> t = [1, 2, 3, 1, 2, 5, 6, 7, 8]
>>> t
[1, 2, 3, 1, 2, 5, 6, 7, 8]
>>> list(set(t))
[1, 2, 3, 5, 6, 7, 8]
>>> s = [1, 2, 3]
>>> list(set(t) - set(s))
[8, 5, 6, 7]
As you can see from the example resu...
Change the name of a key in dictionary
...elete dictionary[old_key].
>>> dictionary = { 1: 'one', 2:'two', 3:'three' }
>>> dictionary['ONE'] = dictionary.pop(1)
>>> dictionary
{2: 'two', 3: 'three', 'ONE': 'one'}
>>> dictionary['ONE'] = dictionary.pop(1)
Traceback (most recent call last):
File "<inp...
Callback functions in C++
...pe.
X.2 "Calling" a callback refers to the syntax to call those objects.
X.3 "Using" a callback means the syntax when passing arguments to a function using a callback.
Note: As of C++17, a call like f(...) can be written as std::invoke(f, ...) which also handles the pointer to member case.
1. Fun...
In c# is there a method to find the max of 3 numbers?
Like Math.Max but takes 3 or params of int?
10 Answers
10
...
How do I merge two dictionaries in a single expression in Python (taking union of dictionaries)?
...
6173
How can I merge two Python dictionaries in a single expression?
For dictionaries x and y, z be...
Syntax for creating a two-dimensional array
...ti[0] = new int[10];
multi[1] = new int[10];
multi[2] = new int[10];
multi[3] = new int[10];
multi[4] = new int[10];
Note that every element will be initialized to the default value for int, 0, so the above are also equivalent to:
int[][] multi = new int[][]{
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
...