大约有 36,010 项符合查询结果（耗时：0.0251秒） [XML]
How to Correctly Use Lists in R?
...that really points out the difference between a list and vector in R:
Why do these two expressions not return the same result?
x = list(1, 2, 3, 4); x2 = list(1:4)
A list can contain any other class as each element. So you can have a list where the first element is a character vector, the second ...
What should my Objective-C singleton look like? [closed]
...
Another option is to use the +(void)initialize method. From the documentation:
The runtime sends initialize to each class in a program exactly one time just before the class, or any class that inherits from it, is sent its first message from within the program. (Thus the method may ne...
How to get rid of punctuation using NLTK tokenizer?
I'm just starting to use NLTK and I don't quite understand how to get a list of words from text. If I use nltk.word_tokenize() , I get a list of words and punctuation. I need only the words instead. How can I get rid of punctuation? Also word_tokenize doesn't work with multiple sentences: dots ar...
What is the best way to repeatedly execute a function every x seconds?
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If your program doesn't have a event loop already, use the sched module, which implements a general purpose event scheduler.
import sched, time
s = sched.scheduler(time.time, time.sleep)
def do_something(sc):
print("Doing stuff...")
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Should I use multiplication or division?
... 0m0.048s
multiplication is 33% faster
Lua:
time lua -e 'for i=1,1e8 do t=12341234234.234 / 2.0 end'
real 0m7.956s
user 0m7.332s
sys 0m0.032s
time lua -e 'for i=1,1e8 do t=12341234234.234 * 0.5 end'
real 0m7.997s
user 0m7.516s
sys 0m0.036s
=> no real difference
LuaJI...
How to check if an element does NOT have a specific class?
How do I check if there isn't a class. For example, I know how to check to see if it has the class "test", but how do I check to see if it doesn't have the class "test"?
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How to uninstall Python 2.7 on a Mac OS X 10.6.4?
...http://www.python.org/ . What directories/files/configuration file entries do I need to remove? Is there a list somewhere?
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NAnt or MSBuild, which one to choose and when?
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I've done a similar investigation this week. Here's what I've been able to determine:
NAnt:
Cross-platform (supports Linux/Mono). It may be handy for installing a web site to multiple targets (that is, Linux Apache and Windows...
How do I script a “yes” response for installing programs?
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does this only work with some command supported to use input from yes, doesn't it? I tried with glance from OpenStack and this not work, I think Expect is more precise for all circumstances
– HVNSweeting...
How do I count a JavaScript object's attributes? [duplicate]
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why don't you just do foo.hasOwnProperty(k). Am I missing something? I mean even JavaScript type derives from Object.prototype, and it will have a hasOwnProperty() method.
– bucabay
Aug 28 '...