Top and bottom line on errorbar with python and seaborn

The capsize parameter should be enough, but for some reason You have to specify the cap.set_markeredgewidth for them to show up too.. Based on: Matplotlib Errorbar Caps Missing.

(_, caps, _) = plt.errorbar(
    x_values, y_values, yerr=y_error, fmt='o', markersize=8, capsize=20)

for cap in caps:
    cap.set_markeredgewidth(1)

returns:

The top and bottom lines on an errorbar are called caps.

To visualize them, just set capsize to a value bigger 0, which is the default value:

plt.errorbar(x, y, yerr=stds, capsize=3)