大约有 40,000 项符合查询结果（耗时：0.0496秒） [XML]
multiprocessing.Pool: When to use apply, apply_async or map?
...
Back in the old days of Python, to call a function with arbitrary arguments, you would use apply:
apply(f,args,kwargs)
apply still exists in Python2.7 though not in Python3, and is generally not used anymore. Nowadays,
f(*args,**kwargs)
is preferred. The...
List of lists changes reflected across sublists unexpectedly
...
When you write [x]*3 you get, essentially, the list [x, x, x]. That is, a list with 3 references to the same x. When you then modify this single x it is visible via all three references to it:
x = [1] * 4
l = [x] * 3
print(f"id(x): {id(x)}")
# id(x): 1405608979...
Draw line in UIView
...re are no errors - I wrote it without Xcode):
UIView *lineView = [[UIView alloc] initWithFrame:CGRectMake(0, 200, self.view.bounds.size.width, 1)];
lineView.backgroundColor = [UIColor blackColor];
[self.view addSubview:lineView];
[lineView release];
// You might also keep a reference to this view
...
MongoDB数据导出导入工具：mongoexport,mongoimport - 大数据 & AI - 清泛...
...ongodb]# ./bin/mongoexport --help
Export MongoDB data to CSV, TSV or JSON files.
options:
--help produce help message
-v [ --verbose ] be more verbose (include multiple times for more
verbosity e.g. -vvvvv)
--version ...
Is it possible to change only the alpha of a rgba background colour on hover?
...255,255,255,0.2);
}
.shadow_method:hover{
box-shadow:none;
}
CodePen examples: http://codepen.io/chrisboon27/pen/ACdka
share
|
improve this answer
|
follow
...
Stock ticker symbol lookup API [closed]
...p like so:
http://d.yimg.com/autoc.finance.yahoo.com/autoc?query=yahoo&callback=YAHOO.Finance.SymbolSuggest.ssCallback
Where query is the company name.
You'll get something like this in return:
YAHOO.Finance.SymbolSuggest.ssCallback(
{
"ResultSet": {
"Query": "ya",
"R...
Delete all files in directory (but not directory) - one liner solution
... = file.listFiles();
for (File f:files)
{if (f.isFile() && f.exists)
{ f.delete();
system.out.println("successfully deleted");
}else{
system.out.println("cant delete a file due to open or error");
} } }}
...
Find what filetype is loaded in vim
...
&filetype for script usage
Minimal example:
echo &filetype
More realistic usage example:
if &filetype ==# 'c' || &filetype ==# 'cpp'
setlocal noexpandtab
endif
& syntax works for all options: https...
What is an existential type?
...e(input);
vm.run(bytecode);
}
});
}
}
An example VM implementation:
class MyVM implements VirtualMachine<byte[]>, VMWrapper {
public byte[] compile(String input) {
return null; // TODO: somehow compile the input
}
public void run(byte[] bytecode)...
Looking for a 'cmake clean' command to clear up CMake output
...simply give cmake the location of the CMakeLists.txt as an argument. For example: cd <location-of-cmakelists>/build && cmake ... (From @ComicSansMS)
share
|
improve this answer
...