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Python None comparison: should I use “is” or ==?

...ject None, so when you do my_var is None, you're checking whether they actually are the same object (not just equivalent objects) In other words, == is a check for equivalence (which is defined from object to object) whereas is checks for object identity: lst = [1,2,3] lst == lst[:] # This is Tr...
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How to use pull to refresh in Swift?

...lf.tableView.reloadData() and self.refreshControl?.endRefreshing() in the callback? – Qian Chen Dec 6 '15 at 19:58 Exa...
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Check if a value is within a range of numbers

...u're asking a question about numeric comparisons, so regular expressions really have nothing to do with the issue. You don't need "multiple if" statements to do it, either: if (x >= 0.001 && x <= 0.009) { // something } You could write yourself a "between()" function: function b...
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What is the curiously recurring template pattern (CRTP)?

... curiously recurring, isn't it? :) Now, what does this give you? This actually gives the X template the ability to be a base class for its specializations. For example, you could make a generic singleton class (simplified version) like this template <class ActualClass> class Singleton { ...
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Android OpenGL ES and 2D

...ur canvas with the proper GL flags for 2D (sprite) rendering. You should really take a look at SpriteMethodTest by the same author of replica island: http://code.google.com/p/apps-for-android/source/browse/trunk/SpriteMethodTest See this question where I posted my own code: Using OpenGL to replace ...
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JavaScript listener, “keypress” doesn't detect backspace?

...s invoked only for character (printable) keys, KeyDown event is raised for all including nonprintable such as Control, Shift, Alt, BackSpace, etc. UPDATE: The keypress event is fired when a key is pressed down and that key normally produces a character value Reference. ...
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How do I size a UITextView to its content?

... Tested on iOS 7 to resize an UITextView into an UITableViewCell. Works really great. This is the only answer that finally worked for me. Thanks! – Alex Nov 30 '13 at 18:40 39 ...
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Why does HTML5 form-validation allow emails without a dot?

... I wonder when the last time someone actually sent an email to localhost! – Matthew Lock May 19 '17 at 3:14 2 ...
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What's the (hidden) cost of Scala's lazy val?

...nswered Jun 15 '10 at 7:51 oxbow_lakesoxbow_lakes 127k5252 gold badges305305 silver badges442442 bronze badges ...
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GDB missing in OS X v10.9 (Mavericks)

... I installed via brew, and keep getting "_____: not in executable format: File format not recognized" when I try to load an executable. Can anyone comment on how they got a successful install? – Parker ...