Read a file line by line from S3 using boto?

Question

I have a csv file in S3 and I\'m trying to read the header line to get the size (these files are created by our users so they could be almost any size). Is there a way to do

Answer 1

With boto3 you can access a raw stream and read line by line. Just note raw stream is a private property for some reason

s3 = boto3.resource('s3', aws_access_key_id='xxx', aws_secret_access_key='xxx')
obj = s3.Object('bucket name', 'file key')

obj.get()['Body']._raw_stream.readline() # line 1
obj.get()['Body']._raw_stream.readline() # line 2
obj.get()['Body']._raw_stream.readline() # line 3...