Add text flush left below plot in python - matplotlib

Question

I'd like to add text beneath a plot, which includes the source of the used data.
It should be positioned at the edge of the image, so beneath the longest ytick and if possible at a fixed vertical distance to the x-axis.
My approach:
import matplotlib.pyplot as plt
country = ['Portugal','Spain','Austria','Italy','France','Federal Republic of Germany']
value = [6,8,10,12,14,25]
plt.figure(figsize=(4,4))
plt.barh(country,value)
plt.xlabel('x-axis')
plt.text(-18,-2.5,'Source: blablablablablablablablablablablablablablablablabla',ha='left')
Plot of the code
I used plt.text(). My problem with the command is, that I have to manually try x and y values (in the code: -18,-2.5) for different plots.
Is there a better way?
Thanks in advance.

Answer 1

Firstly, I got the box info of yticklabels, and then got the leftmost x location for all the yticklabels. Finally, the blended transform method was used to add text with some location adjustments.
import matplotlib.pyplot as plt
from matplotlib.transforms import IdentityTransform
import matplotlib.transforms as transforms
country = ['Portugal','Spain','Austria','Italy','France','Federal Republic of Germany']
value = [6,8,10,12,14,25]
plt.figure(figsize=(4,4))
plt.barh(country,value)
plt.xlabel('x-axis')
ax = plt.gca()
fig =plt.gcf()
fig.tight_layout()
fig.canvas.draw()
labs = ax.get_yticklabels()
xlocs = []
for ilab in labs:
xlocs.append(ilab.get_window_extent().x0)
print(xlocs)
x0 = min(xlocs)
trans = transforms.blended_transform_factory(IdentityTransform(), ax.transAxes)
plt.text(x0-2.5,-0.2,'Source: blablablablablablablablablablablablablablablablabla',ha='left',transform=trans)
plt.savefig("flush.png",bbox_inches="tight")