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Extract elements of list at odd positions
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Solution
Yes, you can:
l = L[1::2]
And this is all. The result will contain the elements placed on the following positions (0-based, so first element is at position 0, second at 1 etc.):
1, 3, 5
so the result (actual numbers) will be:
2, 4, 6
Explanation
The [1::2]...
The preferred way of creating a new element with jQuery
...
I personally think that it's more important for the code to be readable and editable than performant. Whichever one you find easier to look at and it should be the one you choose for above factors.
You can write it as:
$('#box').ap...
Email Address Validation in Android on EditText [duplicate]
... target) {
return (!TextUtils.isEmpty(target) && Patterns.EMAIL_ADDRESS.matcher(target).matches());
}
Kotlin:
fun CharSequence?.isValidEmail() = !isNullOrEmpty() && Patterns.EMAIL_ADDRESS.matcher(this).matches()
Edit: It will work On Android 2.2+ onwards !!
Edit: Added miss...
In android studio,cannot load 2 facets-unknown facet type:android and android-gradle
...nabled, so toggling the check-box sorted it)
Not sure if my cause was installing Flutter, but I did have to disable the Flutter plugin before I could build again.
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How do I 'overwrite', rather than 'merge', a branch on another branch in Git?
...(git commit-tree -m "Throw away branch 'A'" -p A -p B B^{tree})
This basically acts like the (non-existent) merge -s theirs strategy.
You can find the resulting history in the plumbing branch of the demo repository
Not very readable and not as easy to remember compared to the -s ours switch, but it...
select、poll、epoll之间的区别总结[整理] - C/C++ - 清泛网 - 专注C/C++及内核技术
...1、select实现
select的调用过程如下所示：
（1）使用copy_from_user从用户空间拷贝fd_set到内核空间
（2）注册回调函数__pollwait
（3）遍历所有fd，调用其对应的poll方法（对于socket，这个poll方法是sock_poll，sock_poll根据情况会调用到...
django: BooleanField, how to set the default value to true?
...fields/#django.forms.Field.initial ) like
class MyForm(forms.Form):
my_field = forms.BooleanField(initial=True)
If you're using a ModelForm, you can set a default value on the model field ( https://docs.djangoproject.com/en/2.2/ref/models/fields/#default ), which will apply to the resulting M...
What is an xs:NCName type and when should it be used?
...s, then they are NCNames.
xs:string puts no restrictions on your names at all, but xs:NCName basically disallows ":" to appear in the string.
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How to play a local video with Swift?
...
class ViewController: UIViewController {
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
playVideo()
}
private func playVideo() {
guard let path = Bundle.main.path(forResource: "video", ofType:"m4v") else {
debugPrint("...
How do I create a file and write to it in Java?
...te that each of the code samples below may throw IOException. Try/catch/finally blocks have been omitted for brevity. See this tutorial for information about exception handling.
Note that each of the code samples below will overwrite the file if it already exists
Creating a text file:
PrintWriter...