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numpy.fromiter

numpy.fromiter(iterable, dtype, count=-1)

Create a new 1-dimensional array from an iterable object.

Parameters :

iterable : iterable object

An iterable object providing data for the array.

dtype : data-type

The data-type of the returned array.

count : int, optional

The number of items to read from iterable. The default is -1, which means all data is read.

Returns :

out : ndarray

The output array.

Notes

Specify count to improve performance. It allows fromiter to pre-allocate the output array, instead of resizing it on demand.

Examples

>>> iterable = (x*x for x in range(5))
>>> np.fromiter(iterable, np.float)
array([  0.,   1.,   4.,   9.,  16.])