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Add up a column of numbers at the Unix shell
... . . .| x=$(echo <(cat)); echo $((0+${x// /+}+0)) if you want all bash all the time:
– qneill
Apr 3 '15 at 23:31
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Pandas aggregate count distinct
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How about either of:
>>> df
date duration user_id
0 2013-04-01 30 0001
1 2013-04-01 15 0001
2 2013-04-01 20 0002
3 2013-04-02 15 0002
4 2013-04-02 30 0002
>>> df.groupby("date").agg({"duration": np.sum, "use...
How to specify the default error page in web.xml?
... 2.5, there's no other way than specifying every common HTTP error individually. You need to figure which HTTP errors the enduser could possibly face. On a barebones webapp with for example the usage of HTTP authentication, having a disabled directory listing, using custom servlets and code which ca...
AngularJS: Is there any way to determine which fields are making a form invalid?
...lowing code in an AngularJS application, inside of a controller,
which is called from an ng-submit function, which belongs to a form with name profileForm :
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Max parallel http connections in a browser?
...server (comet, reverse ajax, etc). It works ok, but I see the browser only allows two suspended connections to a given domain simultaneously. So if a user is looking at my website in Tab1 of their browser, then also tries loading it in Tab2, they've used up the two allowed connections to my site.
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CSS Box Shadow Bottom Only [duplicate]
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Do this:
box-shadow: 0 4px 2px -2px gray;
It's actually much simpler, whatever you set the blur to (3rd value), set the spread (4th value) to the negative of it.
share
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impr...
Android Camera : data intent returns null
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Really helpful answer I wish I could accept it for others to find the solution more efficiently.
– user1160020
May 3 '13 at 13:32
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How does StartCoroutine / yield return pattern really work in Unity?
...rocesses, like gameplay triggers, that do nothing most frames, but occasionally are called upon to do critical work. And you’ve got assorted processes between the two.
Whenever you’re creating a process that will take place over multiple frames – without multithreading – you need to fin...
std::shared_ptr thread safety explained
...ly regarding your original 3 questions.
But the ending part of your edit
Calling reset() in thread IV will delete previous instance of A class created in first thread and replace it with new instance? Moreover after calling reset() in IV thread other threads will see only newly created object?
is ...
网站伪静态Rewrite重写中文路径时乱码 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...定：
“…Only alphanumerics [0-9a-zA-Z], the special characters “$-_.+!*’(),” [not including the quotes - ed], and reserved characters used for their reserved purposes may be used unencoded within a URL.”
“只有字母和数字[0-9a-zA-Z]、一些特殊符号“$-_.+!*’(),...