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Grouping functions (tapply, by, aggregate) and the *apply family
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Reset select2 value and show placeholder
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edited Jan 24 '17 at 15:20
Hakan Fıstık
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Different ways of clearing lists
..., 3]
>>> b = a
>>> del a[:] # equivalent to del a[0:len(a)]
>>> print(a)
[]
>>> print(b)
[]
>>> a is b
True
You could also do:
>>> a[:] = []
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How can I extend typed Arrays in Swift?
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ggplot with 2 y axes on each side and different scales
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Sometimes a client wants two y scales. Giving them the "flawed" speech is often pointless. But ...
HTML 5 Favicon - Support?
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The above covers IE up to IE 9. IE 11 accepts PNG favicons, however, IE 10 does not. Also IE 10 does not read conditional comments thus IE 10 won't show a favicon. With IE 11 and Edge available I don't see IE 10 in widespread use, so I ignore this browser.
For the rest of the browsers we are goin...
How do I get the width and height of a HTML5 canvas?
... and height attributes are not present in the canvas element, the default 300x150 size will be returned. To dynamically get the correct width and height use the following code:
const canvasW = canvas.getBoundingClientRect().width;
const canvasH = canvas.getBoundingClientRect().height;
Or using th...
MongoDB与内存 - 大数据 & AI - 清泛网移动版 - 专注C/C++及内核技术
...p命令结果：
shell> top -p $(pidof mongod)
Mem: 32872124k total, 30065320k used, 2806804k free, 245020k buffers
Swap: 2097144k total, 100k used, 2097044k free, 26482048k cached
VIRT RES SHR %MEM
1892g 21g 21g 69.6
这台MongoDB服务器有没有性能问题？大家可...
Check if string begins with something? [duplicate]
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Use stringObject.substring
if (pathname.substring(0, 6) == "/sub/1") {
// ...
}
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Check if a string has white space
...e input string:
function hasWhiteSpace(s) {
return s.indexOf(' ') >= 0;
}
Or you can use the test method, on a simple RegEx:
function hasWhiteSpace(s) {
return /\s/g.test(s);
}
This will also check for other white space characters like Tab.
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