Write-Download-from-csv

# Write and Reading from S3 is just as easy
# files are referred as objects in S3.  
# file name is referred as key name in S3
# Files stored in S3 are automatically replicated across 3 different availability zones 
# in the region where the bucket was created.

# http://boto3.readthedocs.io/en/latest/guide/s3.html
def write_to_s3(filename, bucket, key):
    with open(filename,'rb') as f: # Read in binary mode
        return boto3.Session().resource('s3').Bucket(bucket).Object(key).upload_fileobj(f)


def download_from_s3(filename, bucket, key):
    with open(filename,'wb') as f:
        return boto3.Session().resource('s3').Bucket(bucket).Object(key).download_fileobj(f)