`stat = "identity"` doesn't work if combined with `position='stack'`

I’ve noticed that even if I use the flag stat = "identity" in a stacked bar plot, this doesn’t resolve and defaults to the "count" option.

Here is an example of how you can replicate the issue:

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

df = pd.DataFrame({'device': ['Computers', 'Computers', 'Mobile', 'Mobile', 'Tablets', 'Tablets'],
                  'conversion_type': ['conversions', 'cross-device', 'conversions', 'cross-device', 'conversions', 'cross-device'],
                  'revenue': list(np.random.normal(loc=5000, scale=1000, size=6))})
ggplot(df, aes(x='device', y='revenue', fill='conversion_type')) + \
    geom_bar(stat='identity', position='stack')

[IamGianluca]

I’m not sure how easy is to fix this, but if someone if willing to mentor me, I wouldn’t mind to contribute a fix. I’m not very familiar with the codebase though.

[simlmx]

Same version of matplotlib, running everything in a jupyter notebook. However while trying to run it again, I got your result (all blue), and then when I killed and restarted my jupyter notebook a few times, sometimes I got my result (proper coloring) and sometimes your result (all blue). I have no idea what’s going on…