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Bogus foreign key constraint fail
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On demand, now as an answer...
When using MySQL Query Browser or phpMyAdmin, it appears that a new connection is opened for each query (bugs.mysql.com/bug.php?id=8280), making it neccessary to write all the drop statements in one query, eg.
SET FOREIGN_KEY_CHECKS=0;
DROP TABLE my_first_...
Easy pretty printing of floats in python?
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It's an old question but I'd add something potentially useful:
I know you wrote your example in raw Python lists, but if you decide to use numpy arrays instead (which would be perfectly legit in your example, because you seem to be dealing with arrays of numbers), there is ...
Can someone explain the traverse function in Haskell?
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traverse is the same as fmap, except that it also allows you to run effects while you're rebuilding the data structure.
Take a look at the example from the Data.Traversable documentation.
data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
The Functor instance of Tr...
How to apply a function to two columns of Pandas dataframe
Suppose I have a df which has columns of 'ID', 'col_1', 'col_2' . And I define a function :
12 Answers
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How can I selectively merge or pick changes from another branch in Git?
...e over which approach is 'correct'? Consider the difference between files & commits (see Remarks at bottom). OP wants to merge FILES & does not mention COMMITS. The higher-voted answer is specific to files; the accepted answer uses cherry-pick, which is specific to commits. Cherry-pick may b...
RGB to hex and hex to RGB
...ny required zeroes once the leading 1 is stripped off using slice(). For example, if r and g were both zero and b was 51, ((r << 16) + (g << 8) + b).toString(16) would return the string "33"; add 1 << 24 and you get "1000033". Then strip the 1 and you're there.
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How do I typedef a function pointer with the C++11 using syntax?
...entifier from the pointer:
using FunctionPtr = void (*)();
Here is an Example
If you want to "take away the uglyness", try what Xeo suggested:
#include <type_traits>
using FunctionPtr = std::add_pointer<void()>::type;
And here is another demo.
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How would one call std::forward on all arguments in a variadic function?
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You would do:
template <typename ...Params>
void f(Params&&... params)
{
y(std::forward<Params>(params)...);
}
The ... pretty much says "take what's on the left, and for each template parameter, unpack it accordingly."
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public friend swap member function
...ument member function swap, such as:
struct vector
{
void swap(vector&) { /* swap members */ }
};
Naturally, then, our class should too, right? Well, not really. The standard library has all sorts of unnecessary things, and a member swap is one of them. Why? Let's go on.
What we should...
Where is PHP.ini in Mac OS X Lion? Thought it was in /usr/local/php5/lib
I wanted to run some PHP right on my Mac, uncommented httpd.conf, activated web sharing, installed MySQL etc.
I can't seem to find my PHP files, most importantly, PHP.ini.
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