S3根据文件key下载文件数据

S3文档

import boto3

s3 = boto3.resource('s3')

obj = s3.Object(bucket, key)
obj.get()['Body'].read().decode('utf-8') 

import boto3
import json

s3 = boto3.client('s3')

obj = s3.Object(bucket, key)
# s3.Object(bucket_name=u'dev-fastgear', key='rating/2019-07-09/444.png')
# obj.get()
{u'AcceptRanges': 'bytes',
 u'Body': <botocore.response.StreamingBody at 0x7f735fd1d610>,
 u'ContentLength': 101051,
 u'ContentType': 'image/png',
 u'ETag': '"dd768ef356ed1cec48a4d2badd8d025c"',
 u'LastModified': datetime.datetime(2019, 7, 9, 5, 50, 34, tzinfo=tzutc()),
 u'Metadata': {},
 'ResponseMetadata': {'HTTPHeaders': {'accept-ranges': 'bytes',
   'content-length': '101051',
   'content-type': 'image/png',
   'date': 'Wed, 31 Jul 2019 11:22:25 GMT',
   'etag': '"dd768ef356ed1cec48a4d2badd8d025c"',
   'last-modified': 'Tue, 09 Jul 2019 05:50:34 GMT',
   'server': 'AmazonS3',
   'x-amz-id-2': 'ByEj5fvf7XxWh+cXJ4H9Ei8EczTlp9fMrhX8cPLpxC00FJdvlyAGoKfOwmKFkz4V4UAsH2SCac0=',
   'x-amz-request-id': '830F712B632CC662'},
  'HTTPStatusCode': 200,
  'HostId': 'ByEj5fvf7XxWh+cXJ4H9Ei8EczTlp9fMrhX8cPLpxC00FJdvlyAGoKfOwmKFkz4V4UAsH2SCac0=',
  'RequestId': '830F712B632CC662',
  'RetryAttempts': 0}}

j = json.loads(obj.get().['Body'].read())

import io
import boto3

client = boto3.client('s3')
bytes_buffer = io.BytesIO()
client.download_fileobj(Bucket=bucket_name, Key=object_key, Fileobj=bytes_buffer)
byte_value = bytes_buffer.getvalue()
str_value = byte_value.decode() #python3, default decoding is utf-8