Zooming in a graph using zoomed_inset_axes python

I just start learning python three mounths ago, now I want to plot a graph and zoom on a part of it, I am using the code below but the result I get is not what I expected, any ideas how to adjust the zoom part?

#L is an array (19,)
fig, ax = plt.subplots() 
ax.plot(L)
axins = zoomed_inset_axes(ax, zoom=1, loc=1) 
axins.plot(L)
axins.set_ylim(ymin=0,ymax=0.280)
axins.set_xlim(xmin=16,xmax=18) 
plt.yticks(visible=False)
plt.xticks(visible=False)
mark_inset(ax, axins, loc1=1, loc2=4)
plt.show()