Plotnine 条形图按变量顺序

Question

我有一个关于订购条形图的问题。例如:

http://pythonplot.com/#bar-counts

(ggplot(mpg) +
aes(x='manufacturer') +
geom_bar(size=20) +
coord_flip() +
ggtitle('Number of Cars by Make')
)

如何按“mpg”排序？

Answer 1

感谢has2k1:https://github.com/has2k1/plotnine/issues/94

如果 x 映射是有序分类，则受到尊重。

from plydata import *
from plotnine import *
from plotnine.data import mpg

# count the manufacturer and sort by the count (see, plydata documentation
# or find out how to do the same thing using raw pandas)
m_categories = (
    mpg
    >> count('manufacturer', sort=True)
    >> pull('manufacturer')
)

df = mpg.copy()
df['manufacturer'] = pd.Categorical(df['manufacturer'],     categories=m_categories, ordered=True)

(ggplot(df) + 
   aes(x='manufacturer') +
geom_bar(size=20) + 
coord_flip() +
ggtitle('Number of Cars by Make')
)