Upload a file to AWS S3 with multipart uploads using the boto3 python client.

upload.py

# https://boto3.amazonaws.com/v1/documentation/api/latest/guide/quickstart.html
import boto3

# https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html
s3Client = boto3.client('s3')
s3 = boto3.resource('s3')

# https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#S3.Client.create_multipart_upload
multipart_upload = s3Client.create_multipart_upload(
    ACL='public-read',
    Bucket='multipart-using-boto',
    ContentType='video/mp4',
    Key='movie.mp4',
)

print("UploadId: ", multipart_upload['UploadId'])
part_number = 1
parts = []

with open('movie.mp4', 'rb') as f:
    while True:
        piece = f.read(10000000) # roughly 10 mb parts
        if piece == b'':
            break  # end of file
        
        # https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#multipartuploadpart
        uploadPart = s3.MultipartUploadPart(
            'multipart-using-boto', 'movie.mp4', multipart_upload['UploadId'], part_number)
        uploadPartResponse = uploadPart.upload(
            Body=piece,
        )
        print('uploaded part ', part_number, ' with Etag ', uploadPartResponse['ETag'])
        parts.append({
            'PartNumber': part_number,
            'ETag': uploadPartResponse['ETag']
        })
        part_number += 1

print(parts)

# https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/s3.html#S3.Client.complete_multipart_upload
completeResult = s3Client.complete_multipart_upload(
    Bucket='multipart-using-boto',
    Key='movie.mp4',
    MultipartUpload={
        'Parts': parts
    },
    UploadId=multipart_upload['UploadId'],
)

print(completeResult)