axis : integer, optional
Axis along which to perform the operation. The default is to perform
the operation on a flattened view of the input series.
dtype : type
Type to use in computing the standard deviation. For arrays of
integer type the default is float32, for arrays of float types it
is the same as the array type.
out : ndarray
Alternative output array in which to place the result. It must have
the same shape as the expected output but the type will be cast if
necessary.
ddof : integer, optional
Means Delta Degrees of Freedom. The divisor used in calculations
is Nddof.
period : {None, tuple}, optional
Reference period of the computation, as a tuple (starting date, ending date)
If None, use the reference period of the input series.
