geom_bar() of ggplot in Python displaying all bars as having heights of unity

Question

I'm looking to plot of the below dataframe median_area against disturbance_code in year 2020 using ggplot in Python.

scenario | year | disturbance_code | median_area
------------------------------------------------
Base     | 2020 | 1001             | 14264
Base     | 2020 | 1002             | 6637
Base     | 2020 | 1003             | 18190
Base     | 2021 | 1001             | 15000
Base     | 2021 | 1002             | 3615
Base     | 2021 | 1003             | 3132

My code is, very simply:

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

data # this is the dataframe above - it comes from elsewhere in my actual code

ggplot(aes(x = 'disturbance_code', y = 'median_area', fill = 'scenario'), data = 
    data_frame[data_frame['year'] == int(2020)]) +\
    theme_bw() +\
    geom_bar(stat = 'identity', position = 'dodge') +\
    labs(x = 'Severity', y = 'Area burned (ha)')

This gives the following plot:

However, what's very strange is that a simple replacement of geom_bar() with geom_line gives:

Any help on why this is would be appreciated.

Answer 1

Identical question here. The answer, in short, is to replace y = 'median_area' with weight = 'median_area'.