Axes.
fill_betweenx
(y, x1, x2=0, where=None, step=None, interpolate=False, *, data=None, **kwargs)¶Fill the area between two vertical curves.
The curves are defined by the points (x1, y) and (x2, y). This creates one or multiple polygons describing the filled area.
You may exclude some vertical sections from filling using where.
By default, the edges connect the given points directly. Use step if the filling should be a step function, i.e. constant in between y.
Parameters:  y : array (length N)
x1 : array (length N) or scalar
x2 : array (length N) or scalar, optional, default: 0
where : array of bool (length N), optional, default: None
interpolate : bool, optional
step : {‘pre’, ‘post’, ‘mid’}, optional



Returns: 


Other Parameters:  
**kwargs

See also
fill_between
Notes
Note
In addition to the above described arguments, this function can take a data keyword argument. If such a data argument is given, the following arguments are replaced by data[<arg>]: