Python数据分析---matplotlib可视化(饼状图)

import matplotlib.pyplot as plt
import pandas as pd
import itertools
plt.rcParams['font.family']='sans-serif'
plt.rcParams['font.sans-serif']='SimHei'
df=pd.read_excel('d:/2018-2019年空气质量均值.xlsx')
df2=pd.read_excel('d:/2018-2019年空气质量均值.xlsx',1)



# Pie chart, where the slices will be ordered and plotted counter-clockwise:
colNames=["二氧化硫","氮氧化物","烟尘","排放总量"]
years=["2018","2019"]
regionTypes=["省辖市","市辖区"]
def getPlot(colName,year,regionType):
    df22=df2
    if regionType=="市辖区":
        df22=df2[df2['城市名']!='济源市']
    g=df22.groupby(df22['城市名']).sum()
    colStr='%s年%s_%s'%(year,colName,regionType)
    explode = g[colStr].map(lambda x:0.1)  # only "explode" the 2nd slice (i.e. 'Hogs')

    
 

    sizes=g[colStr].apply(round)
    labels=g.index
    labels=sizes.reset_index().to_dict('records')
    labels=map(lambda x:'%s(%dt)'%(x['城市名'],x[colStr]),labels)
    labels=list(labels)
    fig1, ax1 = plt.subplots(figsize=(8,8))
    ax1.pie(sizes, explode=explode, labels=labels, autopct='%1.1f%%',
        shadow=True, startangle=90)
    ax1.axis('equal')  # Equal aspect ratio ensures that pie is drawn as a circle.
    title="%s年各地市%s排放量分布(%s)"%(year,colName,regionType)
    plt.title(title)
    plt.savefig(title+'.png')

for colName,year,regionType in itertools.product(colNames,years,regionTypes):


    print(colName,year,regionType)
    getPlot(colName,year,regionType)