更新s3中的元数据

Question

我使用amazobotov2.38编写python脚本来访问我的S3存储桶。在

我想更新bucket中的一个文件（我知道它在S3中称为“key”）。路径是MyBucket/myfile/demo.txt。此外，我还想更新其名为“name”的元数据。下面是我尝试的代码：

# connect to key
conn = boto.connect_s3()
bucket = conn.get_bucket("MyBucket")

my_key = Key(bucket)
my_key.key = "myfile/demo.txt"

# if key exists, then update the file & its metadata
if my_key.exists():
   new_meta_data = {"name": "xyz"}
   # update metadata
   my_key.copy("MyBucket", my_key.name, new_meta_data, preserve_acl=True)
   # update file content in S3 by using the local file demo.txt
   my_key.set_contents_from_filename("demo.txt")

但是，它不起作用。。。我看不到元数据得到更新。为什么？在

Answer 1

您只需更新密钥的本地元数据，然后执行文件更新：

import boto

conn = boto.connect_s3()
bucket = conn.get_bucket("MyBucket")
key = bucket.get_key('myfile/demo.txt')
key.set_metadata('name', 'xyz')
key.set_contents_from_filename('demo.txt')

现在，name应该作为元数据出现在S3中。但是请注意，当您这样做时，ACL可能会更改。在

也可以用key.set_remote_metadata()完成。这不需要您更新密钥的内容（但如果需要，您可以）：

^{pr2}$

Answer 2

以下代码更改boto3中的密钥元数据：

import boto3 as aws

s3 = aws.resource('s3')
obj = s3.Bucket('MyBucket').Object('objectKey')
obj.put(Metadata={'name':'newName'}

必须使用According to the docs，set_metadata。我已经测试过了，下面的代码与boto2一起工作，并更改了meatadata：

^{pr2}$

Answer 3

使用Boto3时，请注意，如果将“put_object”与元数据一起使用，这将更改您的实际元数据，如果要使用metadata创建object，然后添加元数据或更新现有元数据，请使用以下方法：

import sys
import os 
import boto3
from boto3 import client

param_1= sys.argv[1] 
param_2= sys.argv[2] 
param_3= sys.argv[3]  
param_4= sys.argv[4]
param_5= sys.argv[5]

objectNMAE='THIEF.jpg'

s3ressource = client(
    service_name='s3', 
    endpoint_url= param_3,
    aws_access_key_id= param_1,
    aws_secret_access_key=param_2,
    use_ssl=True,
    )

def createmetdata(bucketname,objectname):
    s3ressource.upload_file(objectname, bucketname, objectname, ExtraArgs={"Metadata": {"metadata1":"ImageName","metadata2":"ImagePROPERTIES" ,"metadata3":"ImageCREATIONDATE"}})

def ADDmetadata(bucketname,objectname):
    s3_object = s3ressource.get_object(Bucket=bucketname, Key=objectname)
    k = s3ressource.head_object(Bucket = bucketname, Key = objectname)
    m = k["Metadata"]
    m["new_metadata"] = "ImageNEWMETADATA"
    s3ressource.copy_object(Bucket = bucketname, Key = objectname, CopySource = bucketname + '/' + objectname, Metadata = m, MetadataDirective='REPLACE')

def CHANGEmetadata(bucketname,objectname):
    s3_object = s3ressource.get_object(Bucket=bucketname, Key=objectname)
    k = s3ressource.head_object(Bucket = bucketname, Key = objectname)
    m = k["Metadata"]
    m.update({'metadata3':'ImageCREATIONDATEEEEEEEEEEEEEEEEEEEEEEEEEE'})
    s3ressource.copy_object(Bucket = bucketname, Key = objectname, CopySource = bucketname + '/' + objectname, Metadata = m, MetadataDirective='REPLACE')

def readmetadata (bucketname,objectname):
    ALLDATAOFOBJECT = s3ressource.get_object(Bucket=bucketname, Key=objectname)
    ALLDATAOFOBJECTMETADATA=ALLDATAOFOBJECT['Metadata']
    print ALLDATAOFOBJECTMETADATA

createmetdata(param_4,objectNMAE)
readmetadata(param_4,objectNMAE)
ADDmetadata(param_4,objectNMAE)
readmetadata(param_4,objectNMAE)
CHANGEmetadata(param_4,objectNMAE)
readmetadata(param_4,objectNMAE)