S3 upload (multipart upload multipartupload)

s3_multipart_upload.py

# this is a simplified version of seeing how to upload
# referencing from https://gist.github.com/teasherm/bb73f21ed2f3b46bc1c2ca48ec2c1cf5

import boto3
import os
from boto3.s3.transfer import TransferConfig

def upload_to_s3(filename, path):
    bucket_name = 'BUCKET_name' #should be a bucket name
    s3 = boto3.client('s3')
    print("size of the file is " ,os.path.getsize(path))
    if(os.path.getsize(path) < 1024 * 1024 * 5):
        s3.upload_file(path, bucket_name, filename) # multipart upload does not support multipart upload for a file less than 5MB
        return "size is too small for multipart upload"
    multipart_upload = s3.create_multipart_upload(Bucket=bucket_name,Key=filename)
    parts = upload_parts(multipart_upload["UploadId"], path, filename)
    result = complete(multipart_upload["UploadId"], parts, filename)
    print(result)
    return " none"
  
def upload_parts(mpu_id, path, filename):
    parts = []
    uploaded_bytes = 0
    with open(path, "rb") as f:
        i = 1
        while True:
            data = f.read(1024 * 1024 * 5) # a part must be larger than 5MB, except for the last one
            if not len(data):
                break
            part = s3.upload_part(
                    Body=data, Bucket=bucket_name, Key=filename, UploadId=mpu_id, PartNumber=i)
            parts.append({"PartNumber": i, "ETag": part["ETag"]})
            uploaded_bytes += len(data)
            i += 1
    return parts
  
def complete(mpu_id, parts, filename):
    result = s3.complete_multipart_upload(
        Bucket=bucket_name,
        Key=filename,
        UploadId=mpu_id,
        MultipartUpload={"Parts": parts})
    return result