大约有 40,000 项符合查询结果（耗时：0.0502秒） [XML]
How do I select a random value from an enumeration?
...ve an array of all values. Then select a random array item.
static Random _R = new Random ();
static T RandomEnumValue<T> ()
{
var v = Enum.GetValues (typeof (T));
return (T) v.GetValue (_R.Next(v.Length));
}
Test:
for (int i = 0; i < 10; i++) {
var value = RandomEnumValue&l...
Creating C formatted strings (not printing them)
...nts are ignored by the function.
Example:
// Allocates storage
char *hello_world = (char*)malloc(13 * sizeof(char));
// Prints "Hello world!" on hello_world
sprintf(hello_world, "%s %s!", "Hello", "world");
share
...
How can you dynamically create variables via a while loop? [duplicate]
...uvwxyz')
print '\n'.join(repr(u) for u in globals() if not u.startswith('__'))
for i in xrange(8):
globals()[''.join(random.sample(alphabet,random.randint(3,26)))] = random.choice(alphabet)
print
print '\n'.join(repr((u,globals()[u])) for u in globals() if not u.startswith('__'))
one resu...
What's the difference between a file descriptor and file pointer?
...ture returned by fopen
typedef struct
{
unsigned char *_ptr;
int _cnt;
unsigned char *_base;
unsigned char *_bufendp;
short _flag;
short _file;
int __stdioid;
char *__newbase;
#ifdef _THREAD_SAFE
v...
Repeat a task with a time delay?
...er());
private Runnable mStatusChecker;
private int UPDATE_INTERVAL = 2000;
/**
* Creates an UIUpdater object, that can be used to
* perform UIUpdates on a specified time interval.
*
* @param uiUpdater A runnable containing the update ro...
Count how many records are in a CSV Python?
...
You need to count the number of rows:
row_count = sum(1 for row in fileObject) # fileObject is your csv.reader
Using sum() with a generator expression makes for an efficient counter, avoiding storing the whole file in memory.
If you already read 2 rows to start ...
How to delete last item in list?
... then:
#!/usr/bin/env python
# coding: utf-8
from timer import Timer
if __name__ == '__main__':
a, record = None, []
while not a == '':
with Timer() as t: # everything in the block will be timed
a = input('Type: ')
record.append(t.elapsed_s)
# drop the last...
How to open link in new tab on html?
...
Set the 'target' attribute of the link to _blank:
<a href="#" target="_blank" rel="noopener noreferrer">Link</a>
Edit: for other examples, see here: http://www.w3schools.com/tags/att_a_target.asp
(Note: I previously suggested blank instead of _blank beca...
How to call a parent method from child class in javascript?
...cessing the parent constructor's prototype methods is possible through the __proto__ property (I am pretty sure there will be fellow JS coders to complain that it's depreciated) which is depreciated but at the same time discovered that it is actually an essential tool for sub-classing needs (especia...
How efficient is locking an unlocked mutex? What is the cost of a mutex?
...tefultask-testsuite/blob/b69b112e2e91d35b56a39f41809d3e3de2f9e4b8/src/mutex_test.cxx
Note that it has a few hardcoded values specific for my box (xrange, yrange and rdtsc overhead), so you probably have to experiment with it before it will work for you.
The graph it produces in that state is:
T...