Python数据分析---matplotlib可视化(柱状图-月份)

import matplotlib
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd

plt.rcParams['font.family']='sans-serif'
plt.rcParams['font.sans-serif']='SimHei'
df=pd.read_excel('d:/网络收集数据.xlsx')

colNames=["PM25","PM10","SO2","NO2","优良天数"]
 

labels=df.月份
def getPlot(colName):
    
    dx =df['%s_2018年'%colName].apply(round)
    dy = df['%s_2019年'%colName].apply(round)
    x = np.arange(len(labels))  # the label locations
    width = 0.35  # the width of the bars

    fig, ax = plt.subplots()
    rects1 = ax.bar(x - width/2, dx, width, label='2018')
    rects2 = ax.bar(x + width/2, dy, width, label='2019')

    # Add some text for labels, title and custom x-axis tick labels, etc.
    ylabel='天' if colName=="优良天数" else "微克/立方米"
    ax.set_ylabel(ylabel)
    title='2018-2019年全省%s对比'%colName
    ax.set_title(title)
    ax.set_xticks(x)
    ax.set_xticklabels(labels)
    ax.legend()


    def autolabel(rects):
        """Attach a text label above each bar in *rects*, displaying its height."""
        for rect in rects:
            height = rect.get_height()
            ax.annotate('{}'.format(height),
                    xy=(rect.get_x() + rect.get_width() / 2, height),
                    xytext=(0, 3),  # 3 points vertical offset
                    textcoords="offset points",
                    ha='center', va='bottom')


    autolabel(rects1)
    autolabel(rects2)

    fig.tight_layout()

    plt.savefig(title+'.png')



for colName in colNames:
    print(colName)
    getPlot(colName)