python - Mean line in plot

Question

I have some plot with sale bike on prefer country. It looks like this:

This is my code:

plot12.groupby(['Country','Year']).sum().reset_index()
ax = sn.barplot(x="Year", y="count", hue="Country", data=plot12)
mean = count.mean()
plt.axvline(mean, color='r', linestyle='--')
plt.title('Sprzeda? rowerów w wybranych Państwach')

I would like to put a mean line and next median line, but I get an error:

NameError: name 'count' is not defined

Answer 1

等待大神答复