您可以使用AWS Glue的Python API来实现仅写入最新的分区parquet的功能。以下是一个示例代码：

import boto3
import sys
from awsglue.context import GlueContext
from pyspark.context import SparkContext
from pyspark.sql import SQLContext

# 创建GlueContext
sc = SparkContext()
glueContext = GlueContext(sc)
spark = glueContext.spark_session

# 设置数据源和目标S3路径
source_bucket = 'your-source-bucket-name'
source_prefix = 'your-source-prefix'
target_bucket = 'your-target-bucket-name'
target_prefix = 'your-target-prefix'

# 获取源数据的最新分区
s3_client = boto3.client('s3')
response = s3_client.list_objects_v2(
    Bucket=source_bucket,
    Prefix=source_prefix,
    Delimiter='/'
)
partitions = response['CommonPrefixes']
latest_partition = sorted(partitions, reverse=True)[0]['Prefix']

# 读取最新分区的parquet数据
source_path = f's3://{source_bucket}/{latest_partition}'
source_df = spark.read.parquet(source_path)

# 写入最新分区的parquet数据到目标路径
target_path = f's3://{target_bucket}/{target_prefix}'
source_df.write.parquet(target_path, mode='overwrite')

print('数据写入完成')

请注意，该代码假设您已经正确配置了AWS Glue环境，并且您有访问S3存储桶的权限。您需要将代码中的your-source-bucket-name、your-source-prefix、your-target-bucket-name和your-target-prefix替换为实际的存储桶和前缀。