Plotnine: How to use geom_col and geom_text to display mean by group

Question

I have a dataset that I am using geom_col to visualize using stat='summary'. I can't quite figure out how to use geom_text() to display the mean values. Here is the code and plot I am able to produce:

import pandas as pd
import numpy as np
from plotnine import *

df = pd.DataFrame({'team': {4: 'Tampa Bay Rays',
  8: 'Tampa Bay Rays',
  85: 'Tampa Bay Rays',
  89: 'Tampa Bay Rays',
  1277: 'League',
  1393: 'League',
  3544: 'League',
  3660: 'League'},
 'inning': {4: 1, 8: 1, 85: 2, 89: 2, 1277: 1, 1393: 1, 3544: 2, 3660: 2},
 'value': {4: 3.0,
  8: 1.0,
  85: 1.0,
  89: 0.0,
  1277: 2.0,
  1393: 0.0,
  3544: 2.0,
  3660: 0.0}})

(ggplot(df, aes(x='inning', y='value', fill='team'))
 + geom_col(stat='summary', position='dodge')
 + scale_x_continuous(breaks=np.arange(1,10,1)))

I am looking to add these labels via geom_text(): Those labels are essentially the result of this code, which I was hoping to avoid, and just have plotnine calculate: df[['team','inning','value']].groupby(['team','inning']).mean()

Answer 1

You need to give geom_text the same statistics and position settings as geom_col.

df = pd.DataFrame({'team': {4: 'Tampa Bay Rays',
  8: 'Tampa Bay Rays',
  85: 'Tampa Bay Rays',
  89: 'Tampa Bay Rays',
  1277: 'League',
  1393: 'League',
  3544: 'League',
  3660: 'League'},
 'inning': {4: 1, 8: 1, 85: 2, 89: 2, 1277: 1, 1393: 1, 3544: 2, 3660: 2},
 'value': {4: 3.0,
  8: 1.0,
  85: 1.0,
  89: 0.0,
  1277: 2.0,
  1393: 0.0,
  3544: 2.0,
  3660: 0.0}})

(ggplot(df, aes(x='inning', y='value', fill='team'))
 + geom_col(stat='summary', position='dodge')
 + geom_text(
     aes(label=after_stat("y"), color="team"),
     stat="summary",
     position=position_dodge(width=0.9),
     va="bottom"
   )
 + scale_x_continuous(breaks=np.arange(1,10,1))
 + scale_color_discrete(l=.4) 
)