Python绘图条形图汇总列，由两个不同的列分组

Question

I have a data set:

Year Month Category Count Line
2019   1       a      2    5
2019   2       b      5    7
2018   1       a      7    12

I want to plot a bar chart in chronological order where the y axis is a sum of the Count field and there is a separate secondary axis for the Line column (no sum).

I am having trouble creating that group and sum.

Answer 1

Try:

df['SumCount'] = df.groupby('Year')['Count'].transform('sum')
ax=df.plot(kind='bar', x='Year',y='Line', alpha=.7, color='g', position=1, width =.2)
df.plot(kind='bar', x='Year',y='SumCount', ax=ax, secondary_y=True, alpha=.8, position=0, width=.2)

Output: