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mongodb group values by multiple fields
... $slice just off the basic aggregation result. For "large" results, run parallel queries instead for each grouping ( a demonstration listing is at the end of the answer ), or wait for SERVER-9377 to resolve, which would allow a "limit" to the number of items to $push to an array.
db.books.aggregate(...
Why does running the Flask dev server run itself twice?
...g is the library that supplies Flask with the development server when you call app.run().
See the restart_with_reloader() function code; your script is run again with subprocess.call().
If you set use_reloader to False you'll see the behaviour go away, but then you also lose the reloading function...
How does type Dynamic work and how to use it?
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Scalas type Dynamic allows you to call methods on objects that don't exist or in other words it is a replica of "method missing" in dynamic languages.
It is correct, scala.Dynamic doesn't have any members, it is just a marker interface - the co...
How can I strip all punctuation from a string in JavaScript using regex?
...stion does not specify "for english only". SO is quite international, used all over the world. Anyone who speaks English and has internet access can use it. If the language is not specified in the question, then we should not be making any assumptions. We are in 2017, dammit!
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Loop through files in a directory using PowerShell
How can I change the following code to look at all the .log files in the directory and not just the one file?
4 Answers
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Escaping regex string
...this:
4.2.3 re Module Contents
escape(string)
Return string with all non-alphanumerics backslashed; this is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it.
A simplistic example, search any occurence of the provided string opt...
Python string.join(list) on object array rather than string array
...riments says that the list comprehension one can be a good 60% faster on small lists (experiment run 10^6 times on a list of three object()s). However, their performance is similar on big lists (2nd experiment run once on a 10^7 objects() list).
– gozzilli
Mar ...
How do I use vimdiff to resolve a git merge conflict?
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All four buffers provide a different view of the same file. The top left buffer (LOCAL) is how the file looked in your target branch (what you are merging into). The top right buffer (REMOTE) is how the file looked in your so...
Are lists thread-safe?
... data is not protected. For example:
L[0] += 1
is not guaranteed to actually increase L[0] by one if another thread does the same thing, because += is not an atomic operation. (Very, very few operations in Python are actually atomic, because most of them can cause arbitrary Python code to be call...
How well is Unicode supported in C++11?
...ization library
Input/output library
Regular expressions library
I think all but the first one provide terrible support. I'll get back to it in more detail after a quick detour through your other questions.
Does std::string do what it should?
Yes. According to the C++ standard, this is what ...