import pandas as pd

x, y_max, y_min = [''] * 12, [0] * 12, [0] * 12 for i in range(12):

    file = "2022"

    if i < 9 :

        file += "0"

    file += str(i+1) + ".xlsx"

    df = pd.read_excel(file)

    df1 = df.("日",as_index = False)   

    ma = df1.max().气温#分组后求最大值

    mi = df1.min().气温#分组后求最小值

    x[i] = +" 月 "

    y_max[i] = ma.mean()#求平均

    y_min[i] = mi.mean()

plt.plot(x, y_max, label='最高温度')#绘制折线图plt.plot(x, y_min, label='最低温度')

#设置绘图参数，显示如图c 所示线型图，代码略