Return evenly spaced values within a given interval.
Values are generated within the halfopen interval [start, stop) (in other words, the interval including start but excluding stop). For integer arguments the function is equivalent to the Python builtin range function, but returns an ndarray rather than a list.
When using a noninteger step, such as 0.1, the results will often not be consistent. It is better to use linspace for these cases.
Parameters :  start : number, optional
stop : number
step : number, optional
dtype : dtype


Returns :  arange : ndarray

See also
Examples
>>> np.arange(3)
array([0, 1, 2])
>>> np.arange(3.0)
array([ 0., 1., 2.])
>>> np.arange(3,7)
array([3, 4, 5, 6])
>>> np.arange(3,7,2)
array([3, 5])