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Should Gemfile.lock be included in .gitignore?

...gem, Gemfile.lock should be in your repository. It's used as a snapshot of all your required gems and their dependencies. This way bundler doesn't have to recalculate all the gem dependencies each time you deploy, etc. From cowboycoded's comment below: If you are working on a gem, then DO NOT c...
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Best way to merge two maps and sum the values of same key?

...mutable.Map[Int,Int] = Map(1 -> 109, 3 -> 300, 2 -> 20) Specifically, the binary operator for Map[K, V] combines the keys of the maps, folding V's semigroup operator over any duplicate values. The standard semigroup for Int uses the addition operator, so you get the sum of values for eac...
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How can I rotate an HTML 90 degrees?

... Just as a suggestion to all future readers: always place the prefixed rules before the standards definition. In this case, all browser-prefixed rules should be before the transform: rotate(90deg); rule. The reason would be that typically, you want t...
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Why is iterating through a large Django QuerySet consuming massive amounts of memory?

...rst time you iterate over it. For example, this will print the headline of all entries in the database: for e in Entry.objects.all(): print e.headline So your ten million rows are retrieved, all at once, when you first enter that loop and get the iterating form of the queryset. The wait ...
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Blocks on Swift (animateWithDuration:animations:completion:)

... dat completion block syntax :( – Chris Allinson Sep 25 '16 at 0:19 add a comment  |  ...
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Python Pandas: Get index of rows which column matches certain value

... frame (whose data may be gibabytes). What about dftest? Doesn't this also allocate a very large intermediate object where the returned index may be very small, or even empty. Are these magically optimized away using lazy views. If not then surely there must be an efficient way. ...
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How do I expand a tuple into variadic template function's arguments?

... Here's my code if anyone is interested Basically at compile time the compiler will recursively unroll all arguments in various inclusive function calls <N> -> calls <N-1> -> calls ... -> calls <0> which is the last one and the compiler will o...
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Python: Why is functools.partial necessary?

...rticular) appear to like lambda just fine – I say "most", definitely not all, because Guido and I assuredly are among those "familiar with" (etc) yet think of lambda as an eyesore anomaly in Python... He was repentant of ever having accepted it into Python whereas planned to remove it from Python ...
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Difference between \w and \b regular expression meta characters

...chor like the caret and the dollar sign. It matches at a position that is called a "word boundary". This match is zero-length. There are three different positions that qualify as word boundaries: Before the first character in the string, if the first character is a word character. After the last ...
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Can I implement an autonomous `self` member type in C++?

...question, not the answer. In many cases in software development (and especially maintenance) it is helpful to avoid redundancies in the code, so that changing something in one place does not require you to change code in another place. That's the whole point of auto and decltype or in this case of s...