Question

我想根据文件的上次修改日期从特定的s3存储桶下载文件。

我已经研究了如何连接boto3，并且有很多代码和文档可用于无条件下载文件。我做了一个伪代码


def download_file_s3(bucket_name,modified_date)
    # connect to reseource s3
    s3 = boto3.resource('s3',aws_access_key_id='demo', aws_secret_access_key='demo')

    # connect to the desired bucket
    my_bucket = s3.Bucket(bucket_name)

    # Get files 
    for file in my_bucket.objects.all():

我想完成此功能，基本上，传递一个修改日期，该函数将返回该特定修改日期s3存储桶中的文件。

Answer 1

这是我的测试代码，它将打印具有我设置的日期时间之后的对象的last_modified datetime。

import boto3
from datetime import datetime
from datetime import timezone

s3 = boto3.resource('s3')
response = s3.Bucket('<bucket name>').objects.all()

for item in response:
    obj = s3.Object(item.bucket_name, item.key)
    if obj.last_modified > datetime(2019, 8, 1, 0, 0, 0, tzinfo=timezone.utc):
        print(obj.last_modified)

如果您有特定的日期，那么

import boto3
from datetime import datetime, timezone

s3 = boto3.resource('s3')
response = s3.Bucket('<bucket name>').objects.all()

date = '20190827' # input('Insert Date as a form YYYYmmdd')

for item in response:
    obj = s3.Object(item.bucket_name, item.key)
    if obj.last_modified.strftime('%Y%m%d') == date:
        print(obj.last_modified)

将给出如下结果。

2019-08-27 07:13:04+00:00
2019-08-27 07:13:36+00:00
2019-08-27 07:13:39+00:00

Answer 2

我有一个更好的解决方案或可以自动执行此功能的功能。只需输入存储桶名称和下载路径名称即可。

from boto3.session import Session
from datetime import date, timedelta
import boto3
import re


def Download_pdf_specifc_date_subfolder(bucket_name,download_path)
    ACCESS_KEY = 'XYZ'
    SECRET_KEY = 'ABC'
    Bucket_name=bucket_name

    # code to create a session 
    session = Session(aws_access_key_id=ACCESS_KEY,
              aws_secret_access_key=SECRET_KEY)
    s3 = session.resource('s3')
    bucket = s3.Bucket(Bucket_name)

    # code to get the yesterdays date
    yesterday = date.today() - timedelta(days=1)
    x=yesterday.strftime('20%y-%m-%d')
    print(x)

    #code to add the files to a list which needs to be downloaded
    files_to_downloaded = []
    #code to take all the files from s3 under a specific bucket
    for fileObject in bucket.objects.all():
        file_name = str(fileObject.key)
        last_modified=str(fileObject.last_modified)
        last_modified=last_modified.split()
        if last_modified[0]==x:
    # Enter the specific bucketname in the regex in place of Airports to filter only the particluar subfolder
            if re.findall(r"Airports/[a-zA-Z]+", file_name):
                files_to_downloaded.append(file_name)

     # code to Download into a specific Folder 
    for fileObject in bucket.objects.all():
        file_name = str(fileObject.key)
        if file_name in files_to_downloaded:
            print(file_name)
            d_path=download_path + file_name
            print(d_path)
            bucket.download_file(file_name,d_path)

Download_pdf_specifc_date_subfolder(bucket_name,download_path)

最终，该功能将在特定文件夹中提供结果以及要下载的文件。

如何根据文件修改日期从s3存储桶下载文件？

2 个答案: