`numpy:ediff1d`

Signature

def ediff1d(ary, to_end = None, to_begin = None)

The differences between consecutive elements of an array.

ary : array_like: If necessary, will be flattened before the differences are taken.
to_end : array_like, optional: Number(s) to append at the end of the returned differences.
to_begin : array_like, optional: Number(s) to prepend at the beginning of the returned differences.

ediff1d : ndarray: The differences. Loosely, this is ary.flat[1:] - ary.flat[:-1].

When applied to masked arrays, this function drops the mask information if the to_begin and/or to_end parameters are used.

import numpy as np
x = np.array([1, 2, 4, 7, 0])
np.ediff1d(x)

✓

array([ 1,  2,  3, -7])

np.ediff1d(x, to_begin=-99, to_end=np.array([88, 99]))

✓

array([-99,   1,   2,   3,  -7,  88,  99])

The returned array is always 1D.

y = [[1, 2, 4], [1, 6, 24]]
np.ediff1d(y)

✓

array([ 1,  2, -3,  5, 18])