Pandas组的直方图与matplotlib

Question

我有datafrme，我在两列上执行groupby：

ax = df_all.groupby(['Component', 'SubComponent' ])['SubComponent'].count()

这给了我这个：

--------------------------------------------------
| Component | SubComponent|                      |
--------------------------------------------------
|A          |First        |                     1|
--------------------------------------------------
|           |Second       |                    10|
--------------------------------------------------
|           |Third        |                     6|
--------------------------------------------------
|B          |First        |                     8|
--------------------------------------------------
|           |Second       |                     5|
--------------------------------------------------
|           |Third        |                    17|
--------------------------------------------------

现在我想用它做一个直方图。 每个条形都是Component，每个组件将在SubComponents上划分，显示每个SubComponent的出现次数不同。

使用matplotlib.pyploy有没有简单的方法来完成它？

谢谢， Submi

Answer 1

您可以unstack使用DataFrame.plot.bar：

print (ax.unstack())
SubComponent  First  Second  Third
Component                         
A                 1       4     15
B                 6       2      1

ax.unstack().plot.bar(stacked=True)

print (ax.unstack(0))
Component      A  B
SubComponent       
First          1  6
Second         4  2
Third         15  1

ax.unstack(0).plot.bar(stacked=True)

通知：

What is the difference between size and count in pandas?