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Is explicitly closing files important?

In Python, if you either open a file without calling close() , or close the file but not using try - finally or the " with " statement, is this a problem? Or does it suffice as a coding practice to rely on the Python garbage-collection to close all files? For example, if one does this: ...
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How do I correctly clone a JavaScript object?

... if you know its name, but I don't know of any way to discover it automatically. Yet another snag in the quest for an elegant solution is the problem of setting up the prototype inheritance correctly. If your source object's prototype is Object, then simply creating a new general object with {} wil...
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Java's L number (long) specification

It appears that when you type in a number in Java, the compiler automatically reads it as an integer, which is why when you type in (long) 6000000000 (not in integer's range) it will complain that 6000000000 is not an integer. To correct this, I had to specify 6000000000L . I just learned abo...
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Django MEDIA_URL and MEDIA_ROOT

... answer below; it is a better solution. – Thane Brimhall Apr 6 '16 at 14:14 is this in your app or project urls.py? ...
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How to check if a map contains a key in Go?

...ring) and ok will receive a bool that will be set to true if "foo" was actually present in the map evaluates ok, which will be true if "foo" was in the map If "foo" is indeed present in the map, the body of the if statement will be executed and val will be local to that scope. ...
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Is there a function to make a copy of a PHP array to another?

...ewLarsson raises a point in the comments below. PHP has a special feature called "references". They are somewhat similar to pointers in languages like C/C++, but not quite the same. If your array contains references, then while the array itself is passed by copy, the references will still resolve to...
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Best way to test if a row exists in a MySQL table

...RE ...) and per the documentation, you can SELECT anything. Traditionally, an EXISTS subquery starts with SELECT *, but it could begin with SELECT 5 or SELECT column1 or anything at all. MySQL ignores the SELECT list in such a subquery, so it makes no difference. ...
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FragmentPagerAdapter Exists Only In Android.Support.V4.App (and not Android.App)

...It's a FragmentPagerAdapter for non-support fragments. Android Studio Installation Please add follow Gradle dependencies dependencies { compile 'com.android.support:support-v13:+' } share | ...
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What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]

... This really is not a proper answer as this is not an inherent feature or function of JavaScript and there are innumerable scenarios where one will absolutely not have access to console.log() – Chris Rasys ...
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How does collections.defaultdict work?

... Usually, a Python dictionary throws a KeyError if you try to get an item with a key that is not currently in the dictionary. The defaultdict in contrast will simply create any items that you try to access (provided of course th...