Replace keys in an array based on another lookup/mapping array
$arr[$newkey] = $arr[$oldkey]; unset($arr[$oldkey]);
arrays
What is the difference between np.array() and np.asarray()?
The definition of asarray is: def asarray(a, dtype=None, order=None): return array(a, dtype, copy=False, order=order) So it is like array, except it has fewer … Read more
How do I create an empty array and then append to it in NumPy?
That is the wrong mental model for using NumPy efficiently. NumPy arrays are stored in contiguous blocks of memory. To append rows or … Read more
JavaScript, Node.js: is Array.forEach asynchronous?
No, it is blocking. Have a look at the specification of the algorithm. However a maybe easier to understand implementation is given on … Read more
How to filter an associative array comparing keys with values in an indexed array?
With array_intersect_key and array_flip: var_dump(array_intersect_key($my_array, array_flip($allowed))); array(1) { [“foo”]=> int(1) }
How to map/collect with index in Ruby?
If you’re using ruby 1.8.7 or 1.9, you can use the fact that iterator methods like each_with_index, when called without a block, return … Read more
How to check if an array is empty or exists?
if (typeof image_array !== ‘undefined’ && image_array.length > 0) { // the array is defined and has at least one element } Your … Read more
How to get the last element of an array without deleting it?
How to get the last element of an array without deleting it?
How do I declare an array in Python?
variable = [] Now variable refers to an empty list*. Of course this is an assignment, not a declaration. There’s no way to … Read more
How do I access the ith column of a NumPy multidimensional array?
To access column 0: >>> test[:, 0] array([1, 3, 5]) To access row 0: >>> test[0, :] array([1, 2]) This is covered in … Read more
