大约有 40,000 项符合查询结果（耗时：0.0351秒） [XML]
Finding quaternion representing the rotation from one vector to another
...ion is produced -- check and see for yourself).
// N.B. the arguments are _not_ axis and angle, but rather the
// raw scalar-vector components.
Quaternion(float w, Vector3 xyz);
Quaternion get_rotation_between(Vector3 u, Vector3 v)
{
// It is important that the inputs are of equal length when
...
List comprehension: Returning two (or more) items for each item
...bda x: x + 2
>>> g = lambda x: x ** 2
>>> list(chain.from_iterable((f(x), g(x)) for x in range(3)))
[2, 0, 3, 1, 4, 4]
Timings:
from timeit import timeit
f = lambda x: x + 2
g = lambda x: x ** 2
def fg(x):
yield f(x)
yield g(x)
print timeit(stmt='list(chain.from_itera...
Substitute multiple whitespace with single whitespace in Python [duplicate]
...ce characters that are combined.
To match unicode whitespace:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"\s+")
my_str = _RE_COMBINE_WHITESPACE.sub(" ", my_str).strip()
To match ASCII whitespace only:
import re
_RE_COMBINE_WHITESPACE = re.compile(r"(?a:\s+)")
_RE_STRIP_WHITESPACE = re.co...
Using “label for” on radio buttons
...ds like a clear case to use a checkbox instead :D
– T_D
Mar 13 at 15:16
Ah, no what I meant was one super-label that t...
Better way to check variable for null or empty string?
... what is the purpose of !isset() here? how is it different to is_null()?
– nickf
May 7 '10 at 13:44
2
...
Is it true that one should not use NSLog() on production code?
... line number to make it easier to track down log statements.
#define DEBUG_MODE
#ifdef DEBUG_MODE
#define DebugLog( s, ... ) NSLog( @"<%p %@:(%d)> %@", self, [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
...
What is a regular expression which will match a valid domain name without a subdomain?
...many valid edge cases that I have missed):
^((?!-))(xn--)?[a-z0-9][a-z0-9-_]{0,61}[a-z0-9]{0,1}\.(xn--)?([a-z0-9\-]{1,61}|[a-z0-9-]{1,30}\.[a-z]{2,})$
When choosing a domain validation regex, you should see if the domain matches the following:
xn--stackoverflow.com
stackoverflow.xn--com
stackov...
How to use the PI constant in C++
...ially older) platforms (see the comments below) you might need to
#define _USE_MATH_DEFINES
and then include the necessary header file:
#include <math.h>
and the value of pi can be accessed via:
M_PI
In my math.h (2014) it is defined as:
# define M_PI 3.1415926535897932384...
Javascript - Append HTML to container element without innerHTML
...here are two prerequisite functions needed at the bottom of this post.
xml_add('before', id_('element_after'), '<span xmlns="http://www.w3.org/1999/xhtml">Some text.</span>');
xml_add('after', id_('element_before'), '<input type="text" xmlns="http://www.w3.org/1999/xhtml" />');
...
搭建高可用mongodb集群（三）—— 深入副本集内部机制 - 大数据 & AI - 清...
...为1是不显示的，这里标示出来。
rs.conf();
{
"_id" : "rs0",
"version" : 9,
"members" : [
{
"_id" : 0,
"host" : "192.168.1.136:27017" },
{
...