# numpy.memmap.itemset

method

memmap.itemset(*args)

  Insert scalar into an array (scalar is cast to array’s dtype, if possible)

  There must be at least 1 argument, and define the last argument as item. Then, `a.itemset(*args)` is equivalent to but faster than `a[args] = item`. The item should be a scalar value and args must select a single item in the array a.

  Parameters:
    *args Arguments

      If one argument: a scalar, only used in case a is of size 1. If two arguments: the last argument is the value to be set and must be a scalar, the first argument specifies a single array element location. It is either an int or a tuple.

  Notes

  Compared to indexing syntax, `itemset` provides some speed increase for placing a scalar into a particular location in an `ndarray`, if you must do this. However, generally this is discouraged: among other problems, it complicates the appearance of the code. Also, when using `itemset` (and `item`) inside a loop, be sure to assign the methods to a local variable to avoid the attribute look-up at each loop iteration.

  Examples

      >>> np.random.seed(123)
      >>> x = np.random.randint(9, size=(3, 3))
      >>> x
      array([[2, 2, 6],
             [1, 3, 6],
             [1, 0, 1]])
      >>> x.itemset(4, 0)
      >>> x.itemset((2, 2), 9)
      >>> x
      array([[2, 2, 6],
             [1, 0, 6],
             [1, 0, 9]])