大约有 40,000 项符合查询结果（耗时：0.0413秒） [XML]
How to get the return value from a thread in python?
...ram in param_list] The order will be maintained, and exiting the with will allow result collection. [f.result() for f in futures]
– jayreed1
Jun 4 at 21:29
...
Rails :include vs. :joins
...de functionality was changed with Rails 2.1. Rails used to do the join in all cases, but for performance reasons it was changed to use multiple queries in some circumstances. This blog post by Fabio Akita has some good information on the change (see the section entitled "Optimized Eager Loading")....
How to save an image locally using Python whose URL address I already know?
...
Python 2
Here is a more straightforward way if all you want to do is save it as a file:
import urllib
urllib.urlretrieve("http://www.digimouth.com/news/media/2011/09/google-logo.jpg", "local-filename.jpg")
The second argument is the local path where the file should be s...
Does Javascript pass by reference? [duplicate]
...m very confused about my parameter for the rectangle function. It is actually undefined , and redefined inside the function. There are no original reference. If I remove it from the function parameter, the inside area function is not able to access it.
...
How does type Dynamic work and how to use it?
...
Scalas type Dynamic allows you to call methods on objects that don't exist or in other words it is a replica of "method missing" in dynamic languages.
It is correct, scala.Dynamic doesn't have any members, it is just a marker interface - the co...
Printing without newline (print 'a',) prints a space, how to remove?
... This will consume a bit of memory for the string, but only make a single call to print. Note that string concatenation using += is now linear in the size of the string you're concatenating so this will be fast.
>>> for i in xrange(20):
... s += 'a'
...
>>> print s
aaaaaaaaaa...
Detecting endianness programmatically in a C++ program
...
Is this solution really portable? What if CHAR_BIT != 8 ?
– zorgit
May 30 '15 at 20:12
|
...
Extracting bits with a single multiplication
.....
A multiplication is a bunch of shift-and-add operations. The key is to allow overflow to "shift away" the bits we don't need and put the ones we want in the right place.
Multiplication by 4 (00000100) would shift everything left by 2 and get you to a00b0000 . To get the b to move up we need to...
Keyboard Interrupts with python's multiprocessing Pool
...s to set up the worker processes to ignore SIGINT altogether, and confine all the cleanup code to the parent process. This fixes the problem for both idle and busy worker processes, and requires no error handling code in your child processes.
import signal
...
def init_worker():
signal.sign...
Python: reload component Y imported with 'from X import Y'?
... verse (import this from interactive prompt to see the Zen of Python); and all the reasons why namespaces are a honking great idea (immediate local visual clues that the name's being looked up, ease of mocking/injecting in tests, ability to reload, ability for a module to change flexibly by redefini...