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Efficiently checking if arbitrary object is NaN in Python / numpy / pandas?
My numpy arrays use np.nan to designate missing values. As I iterate over the data set, I need to detect such missing values and handle them in special ways.
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How to sum up an array of integers in C#
Is there a better shorter way than iterating over the array?
12 Answers
12
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What is the easiest way to push an element to the beginning of the array?
...ving trouble remembering between shift and unshift as to which adds to the array and which removes from the array, drop an 'f' from the names mentally and you get an all-too-clear picture as to the direction. (And then you have to remember that these methods don't work on the "end" of the array. ;)
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Convert a list to a dictionary in Python
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You can do it pretty fast without creating extra arrays, so this will work even for very large arrays:
dict(izip(*([iter(a)]*2)))
If you have a generator a, even better:
dict(izip(*([a]*2)))
Here's the rundown:
iter(h) #create an iterator from the array, no copies...
Flat file databases [closed]
... the nature of the flat databases. Are they large or small. Is it simple arrays with arrays in them? if its something simple say userprofiles built as such:
$user = array("name" => "dubayou",
"age" => 20,
"websites" => array("dubayou.com","willwharton.com","...
Can't access object property, even though it shows up in a console log
...ify, is the behaviour of the > button different depending on whether an array is being expanded, or an object?
– Flimm
Oct 4 '18 at 14:41
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In c# what does 'where T : class' mean?
...cifically a reference type which could be a class, interface, delegate, or array type).
See this MSDN article for further details.
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Get Specific Columns Using “With()” Function in Laravel Eloquent
...can be done one by passing a closure function in with() as second index of array like
Post::with(array('user'=>function($query){
$query->select('id','username');
}))->get();
It will only select id and username from other table. I hope this will help others.
Remember that t...
Default template arguments for function templates
...conversion from ‘int’ to ‘int*’, any idea why: ` #include <array> #include <algorithm> #include <functional> template<typename Iterator, typename Comp = std::less<Iterator> > void my_sort(Iterator beg, Iterator end, Comp c = Comp()) { ...
Iterating over a numpy array
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I think you're looking for the ndenumerate.
>>> a =numpy.array([[1,2],[3,4],[5,6]])
>>> for (x,y), value in numpy.ndenumerate(a):
... print x,y
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0 0
0 1
1 0
1 1
2 0
2 1
Regarding the performance. It is a bit slower than a list comprehension.
X = np.zeros((100, 100...