import numpy as np import pandas as pd import matplotlib.pyplot as plt # 读取教学账目数据 teaching_df = pd.read_excel('教学.xlsx') # 读取后勤账目数据 logistics_df = pd.read_excel('后勤.xlsx') # 读取行政账目数据 administrative_df = pd.read_excel('行政.xlsx') # 将各表格的取得日期列转换为日期时间类型，并提取年份作为新列 teaching_df['年份'] = pd.to_datetime(teaching_df['取得日期'], format='%y-%m-%d').dt.year logistics_df['年份'] = pd.to_datetime(logistics_df['取得日期'], format='%y-%m-%d').dt.year administrative_df['年份'] = pd.to_datetime(administrative_df['取得日期'], fo