如何计算同一列中不同值的百分比，并按当年月份分组？

import mysql.connector

# 连接数据库
cnx = mysql.connector.connect(user='your_username', password='your_password',
                              host='your_host', database='your_database')
cursor = cnx.cursor()

# 查询需要的数据
query = ("SELECT column_name, date FROM your_table")

cursor.execute(query)

# 初始化统计字典
statistics = {}

# 遍历查询结果
for (column_name, date) in cursor:
    # 按照年份和月份进行分组
    year_month = date.strftime("%Y-%m")
    
    # 统计同一列中不同值的数量
    if year_month not in statistics:
        statistics[year_month] = {}
    
    if column_name not in statistics[year_month]:
        statistics[year_month][column_name] = 1
    else:
        statistics[year_month][column_name] += 1

# 计算百分比并格式化结果
result = {}
for year_month, data in statistics.items():
    total = sum(data.values())
    result[year_month] = {column_name: count/total*100 for column_name, count in data.items()}

# 打印结果
for year_month, data in result.items():
    print("Year-Month:", year_month)
    for column_name, percentage in data.items():
        print(column_name, "Percentage:", percentage)

# 关闭数据库连接
cursor.close()
cnx.close()