Find indices where elements should be inserted to maintain order.
Find the indices into a sorted array a such that, if the corresponding elements in v were inserted before the indices, the order of a would be preserved.
Parameters:  a : 1D array_like
v : array_like
side : {‘left’, ‘right’}, optional


Returns:  indices : array of ints

Notes
Binary search is used to find the required insertion points.
As of Numpy 1.4.0 searchsorted works with real/complex arrays containing nan values. The enhanced sort order is documented in sort.
Examples
>>> np.searchsorted([1,2,3,4,5], 3)
2
>>> np.searchsorted([1,2,3,4,5], 3, side='right')
3
>>> np.searchsorted([1,2,3,4,5], [10, 10, 2, 3])
array([0, 5, 1, 2])