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How to join (merge) data frames (inner, outer, left, right)
...) will work for these examples because R automatically joins the frames by common variable names, but you would most likely want to specify merge(df1, df2, by = "CustomerId") to make sure that you were matching on only the fields you desired. You can also use the by.x and by.y parameters if the mat...
Any way to make a WPF textblock selectable?
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MySQL connection not working: 2002 No such file or directory
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What are allowed characters in cookies?
...wed characters in both cookie name and value? Are they same as URL or some common subset?
13 Answers
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Why should I avoid std::enable_if in function signatures
...ON_REQUIRES macro here, makes it much nicer to read, and it works in C++03 compilers as well, and it relies on using enable_if in the return type. Also, using enable_if in function template parameters causes problems for overloading, because now the function signature aren't unique causing ambiguous...
When to use IList and when to use List
...change to some other better type without forcing all of your clients to re-compile/update.
– Ash
Sep 12 '10 at 8:53
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Get key by value in dictionary
...re constructive. A perfectly reasonable use case is not "unintended" (list comprehension fits such a use case anyway). A dict can be for multiple things at different times; keys and values have a clear meaning, of course, but "dict items with a given value" is a perfectly reasonable request. The rec...
Better to 'try' something and catch the exception or test if it's possible first to avoid an excepti
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How do I manage MongoDB connections in a Node.js web application?
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The primary committer to node-mongodb-native says:
You open do MongoClient.connect once when your app boots up and reuse
the db object. It's not a singleton connection pool each .connect
creates a new connection pool.
So, to an...
PHP Multidimensional Array Searching (Find key by specific value)
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