自动查找并添加坐标以在由不均匀列表字典制成的箱线图上添加注释（例如计数）

Question

I'm pretty new in programming world and I'm really frustrated to solve a problem which I thought should be really easy...

Case: Let's say I have a Dictionary with uneven Lists; Also the number of Keys(string) & Values(number) could change anytime.

Need: I want to annotate (add text or whatever) some Information (eg count) to each Subplots or Categories (each Key is an individual Category).

Problem: I found many solutions for evenly numbered Categories, which apparently doesn't work for me. eg Solution

I also found some Answers eg Solution , that I should first get the Coordinates of each Keys in the x-line and then do a inverted transformation to work with the "log scales". Which was so far the best solution for me, but unfortunately it does not really fit the Coordinates and I couldn't get & add the points automatically before using plt.show().

I could also guess the coordinates with trial error in the Transformation Method or with Offset eg Solution . But as I said, my Dictionary could change anytime, and then I should do it again every time!

I think there should be much more simpler method to solve this problem, but I couldn't find it.

Here is the simplified example of my Code and what I tried:

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.offsetbox import (TextArea, DrawingArea, OffsetImage,
                                  AnnotationBbox)

dictionary = {}
dictionary["a"] = [1, 2, 3, 4, 5]
dictionary["b"] = [1, 2, 3, 4, 5, 6, 7]

fig, ax = plt.subplots()
ax.boxplot(dictionary.values())
x = ax.set_xticklabels(dictionary.keys())

fig.text(x = 0.25, y = 0, s = str(len(dictionary["a"])))
fig.text(x = 0.75, y = 0, s = str(len(dictionary["b"])))


plt.show()


crd = np.vstack((ax.get_xticks(), np.zeros_like(ax.get_xticks()))).T
ticks = ax.transAxes.inverted().transform(ax.transData.transform(crd))

print(ticks[:,0])



# ab = AnnotationBbox(TextArea("text"), xy=(1, 0), xybox =(0, -30), boxcoords="offset points",pad=0,frameon=False )
# ax.add_artist(ab)

Output of my code

Answer 1

as i understand you may want something like this:

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.offsetbox import (TextArea, DrawingArea, OffsetImage,
                                  AnnotationBbox)

dictionary = {}
dictionary["a"] = [1, 2, 3, 4, 5]
dictionary["b"] = [1, 2, 3, 4, 5, 6, 7]
dictionary["cex"] = [1, 2, 3]

fig, ax = plt.subplots()
ax.boxplot(dictionary.values())
x = ax.set_xticklabels(dictionary.keys())

ticksList=ax.get_xticks()
print (ticksList)
for x in ticksList:
    ax.text(x, 0,str(len(list(dictionary.values())[x-1])),fontdict={'horizontalalignment': 'center'})

fig.show()