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How to reshape data from long to wide format
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+1 and you don't need to rely on external packages, since reshape comes with stats. Not to mention that it's faster! =)
– aL3xa
May 5 '11 at 0:07
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How do you know what to test when writing unit tests? [closed]
... code, or a completely new feature.
Start simple. Don’t go running off and trying to get your head round
a testing framework as well as being
TDD-esque. Debug.Assert works fine.
Use it as a starting point. It doesn’t
mess with your project or create
dependencies.
Start positive. Yo...
Find MongoDB records where array field is not empty
... To me that's the correct approach, since it makes sure the array exists and is not empty.
– LeandroCR
Mar 19 '15 at 14:34
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How can I preview a merge in git?
I have a git branch (the mainline, for example) and I want to merge in another development branch. Or do I?
11 Answers
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Cleanest and most Pythonic way to get tomorrow's date?
What is the cleanest and most Pythonic way to get tomorrow's date? There must be a better way than to add one to the day, handle days at the end of the month, etc.
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How do you debug a regex? [closed]
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You buy RegexBuddy and use its built in debug feature. If you work with regexes more than twice a year, you will make this money back in time saved in no time. RegexBuddy will also help you to create simple and complex regular expressions, and...
Error - trustAnchors parameter must be non-empty
I'm trying to configure my e-mail on Jenkins/Hudson, and I constantly receive the error:
44 Answers
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Gradients on UIView and UILabels On iPhone [duplicate]
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You could also use a graphic image one pixel wide as the gradient, and set the view property to expand the graphic to fill the view (assuming you are thinking of a simple linear gradient and not some kind of radial graphic).
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Redis strings vs Redis hashes to represent JSON: efficiency?
...e cases):
Store the entire object as JSON-encoded string in a single key and keep track of all Objects using a set (or list, if more appropriate). For example:
INCR id:users
SET user:{id} '{"name":"Fred","age":25}'
SADD users {id}
Generally speaking, this is probably the best method in most cas...
Can we have functions inside functions in C++?
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Modern C++ - Yes with lambdas!
In current versions of c++ (C++11, C++14, and C++17), you can have functions inside functions in the form of a lambda:
int main() {
// This declares a lambda, which can be called just like a function
auto print_message = [](std::string message)
{
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