I read the filenames in my S3 bucket by doing
objs = boto3.client.list_objects(Bucket='my_bucket')
while 'Contents' in objs.keys():
objs_contents = objs['Contents']
for i in range(len(objs_contents)):
filename = objs_contents[i]['Key']
Now, I need to get the actual content of the file, similarly to a open(filename).readlines()
. What is the best way?
This question is related to
python
amazon-web-services
amazon-s3
boto3
Using the client instead of resource:
s3 = boto3.client('s3')
bucket='bucket_name'
result = s3.list_objects(Bucket = bucket, Prefix='/something/')
for o in result.get('Contents'):
data = s3.get_object(Bucket=bucket, Key=o.get('Key'))
contents = data['Body'].read()
print(contents)
If you already know the filename
, you can use the boto3
builtin download_fileobj
import boto3
from io import BytesIO
session = boto3.Session()
s3_client = session.client("s3")
f = BytesIO()
s3_client.download_fileobj(bucket_name, filename, f)
f.seek(0)
print(f.getvalue())
You might also consider the smart_open
module, which supports iterators:
from smart_open import smart_open
# stream lines from an S3 object
for line in smart_open('s3://mybucket/mykey.txt', 'rb'):
print(line.decode('utf8'))
and context managers:
with smart_open('s3://mybucket/mykey.txt', 'rb') as s3_source:
for line in s3_source:
print(line.decode('utf8'))
s3_source.seek(0) # seek to the beginning
b1000 = s3_source.read(1000) # read 1000 bytes
Find smart_open
at https://pypi.org/project/smart_open/
When you want to read a file with a different configuration than the default one, feel free to use either mpu.aws.s3_read(s3path)
directly or the copy-pasted code:
def s3_read(source, profile_name=None):
"""
Read a file from an S3 source.
Parameters
----------
source : str
Path starting with s3://, e.g. 's3://bucket-name/key/foo.bar'
profile_name : str, optional
AWS profile
Returns
-------
content : bytes
botocore.exceptions.NoCredentialsError
Botocore is not able to find your credentials. Either specify
profile_name or add the environment variables AWS_ACCESS_KEY_ID,
AWS_SECRET_ACCESS_KEY and AWS_SESSION_TOKEN.
See https://boto3.readthedocs.io/en/latest/guide/configuration.html
"""
session = boto3.Session(profile_name=profile_name)
s3 = session.client('s3')
bucket_name, key = mpu.aws._s3_path_split(source)
s3_object = s3.get_object(Bucket=bucket_name, Key=key)
body = s3_object['Body']
return body.read()
Source: Stackoverflow.com