Draw connected horizontal lines (like free energy diagram)

lineplot.py

def lineplot(x, y, length=None, width=1, connection_style="--", ax=None, **kwargs):
    if ax is None:
        ax = plt.gca()
    if length is None:
        length = length or (max(x) - min(x)) / len(x) * 0.8
    x, y = np.array(x), np.array(y)
    xmin, xmax = x - length / 2, x + length / 2
    lines = ax.hlines(y=y, xmin=xmin, xmax=xmax, **kwargs)
    for i in range(len(x) - 1):
        xs, ys = [xmax[i], xmin[i + 1]], [y[i], y[i + 1]]
        ax.plot(xs, ys, connection_style, color=lines.get_color()[0], linewidth=width)
    return ax