带有进度条的 S3 Python 下载

Question

无法评论我改编此代码的初始线程 (Track download progress of S3 file using boto3 and callbacks)，因此希望有人可以在这里帮助我。我能够使用此代码显示文件上传的进度条，现在我需要对从 AWS S3 下载的文件执行相同的操作。任何帮助将不胜感激！

我知道我需要从 S3 而不是从本地文件系统获取文件的大小。我确定我需要调整一些愚蠢的代码才能使其正常工作。希望有人可以提供一些启示。 :)

def upload_to_aws(local_file, bucket, s3_file):
    s3 = boto3.client('s3', aws_access_key_id=s3ak,
                      aws_secret_access_key=s3sk)

    statinfo = os.stat(local_file)
    up_progress = progressbar.progressbar.ProgressBar(maxval=statinfo.st_size)
    up_progress.start()
    def upload_progress(chunk):
        up_progress.update(up_progress.currval + chunk)

    try:
        s3.upload_file(local_file, bucket, s3_file, Callback=upload_progress)
        up_progress.finish()
        print("Upload Successful")
        return True
    except FileNotFoundError:
        print("The file was not found")
        return False
    except NoCredentialsError:
        print("Credentials not available")
        return False

Answer 1

import os
import boto3
import progressbar
from botocore.exceptions import NoCredentialsError


def download_from_s3(bucket, s3_file, local_file):
    s3 = boto3.client('s3')
    response = s3.head_object(Bucket=bucket, Key=s3_file)
    size = response['ContentLength']
    up_progress = progressbar.progressbar.ProgressBar(maxval=size)
    up_progress.start()

    def upload_progress(chunk):
        up_progress.update(up_progress.currval + chunk)

    try:
        s3.download_file(bucket, s3_file, local_file, 
Callback=upload_progress)
        up_progress.finish()
        print("Download Successful")
        return True
    except FileNotFoundError:
        print("The file was not found")
        return False
    except NoCredentialsError:
        print("Credentials not available")
        return False


resp = download_from_s3(bucket, s3_file, local_file)