dynamodb python工具类

以下是使用Python操作DynamoDB的工具类示例：

import boto3

class DynamoDBTool:
    def __init__(self, table_name):
        self.table_name = table_name
        self.dynamodb = boto3.resource('dynamodb')
        self.table = self.dynamodb.Table(table_name)

    def put_item(self, item):
        self.table.put_item(Item=item)
    def get_item(self, key):
        response = self.table.get_item(Key=key)
        return response.get('Item')

    def update_item(self, key, update_expression, expression_attribute_values):
        self.table.update_item(
            Key=key,
            UpdateExpression=update_expression,
            ExpressionAttributeValues=expression_attribute_values
        )

    def delete_item(self, key):
        self.table.delete_item(Key=key)

使用示例：

# 初始化工具类
dynamodb_tool = DynamoDBTool('my-table')

# 插入数据
item = {'id': '1', 'name': 'John'}
dynamodb_tool.put_item(item)

# 获取数据
key = {'id': '1'}
result = dynamodb_tool.get_item(key)
print(result)

# 更新数据
key = {'id': '1'}
update_expression = 'set #name = :new_name'
expression_attribute_values = {':new_name': 'Mike'}
dynamodb_tool.update_item(key, update_expression, expression_attribute_values)

# 删除数据
key = {'id': '1'}
dynamodb_tool.delete_item(key)