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How can I use map and receive an index as well in Scala?
Is there any List/Sequence built-in that behaves like map and provides the element's index as well?
8 Answers
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Finish an activity from another activity
...When the user clicks modify, call the new Intent or simply finish activity B.
FIRST WAY
In your first activity, declare one Activity object like this,
public static Activity fa;
onCreate()
{
fa = this;
}
now use that object in another Activity to finish first-activity like this,
onCreate(...
Element-wise addition of 2 lists?
...>> %timeit from operator import add;map(add, list1, list2)
10 loops, best of 3: 44.6 ms per loop
>>> %timeit from itertools import izip; [a + b for a, b in izip(list1, list2)]
10 loops, best of 3: 71 ms per loop
>>> %timeit [a + b for a, b in zip(list1, list2)]
10 loops, best...
How to get the difference between two arrays in JavaScript?
Is there a way to return the difference between two arrays in JavaScript?
69 Answers
6...
How to achieve function overloading in C?
... to achieve function overloading in C? I am looking at simple functions to be overloaded like
14 Answers
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How would you make a comma-separated string from a list of strings?
What would be your preferred way to concatenate strings from a sequence such that between every two consecutive pairs a comma is added. That is, how do you map, for instance, ['a', 'b', 'c'] to 'a,b,c' ? (The cases ['s'] and [] should be mapped to 's' and '' , respectively.)
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How do you calculate the average of a set of circular data? [closed]
...xample, I might have several samples from the reading of a compass. The problem of course is how to deal with the wraparound. The same algorithm might be useful for a clockface.
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How to select an element with 2 classes [duplicate]
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You can chain class selectors without a space between them:
.a.b {
color: #666;
}
Note that, if it matters to you, IE6 treats .a.b as .b, so in that browser both div.a.b and div.b will have gray text. See this answer for a comparison between proper browsers and I...
Python if-else short-hand [duplicate]
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The most readable way is
x = 10 if a > b else 11
but you can use and and or, too:
x = a > b and 10 or 11
The "Zen of Python" says that "readability counts", though, so go for the first way.
Also, the and-or trick will fail if ...
scrapy xpath抓取节点的文本innerText、innerHTML、outerHTML - 更多技术 -...
...取节点的文本innerText、innerHTML、outerHTML假设抓取：<p> xx<b>x< b>< p> 抓取p节点本身，得到的内容：<p>xx<b>x< b>< p>response xpath(& 39; div[@class="question"] div[2] div[2] div[1] p[1]& 39;) extract() 抓 假设抓取：
<p>
xx<b>x</b>
</p>
scrapy代码：
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