A script to loop through a list of bucket objects that would exceed the max-keys.

s3_continuation.py

#!/usr/bin/env python
import boto3

client = boto3.client('s3')
bucket = 'you-s3-bucket'
prefix = 'a-prefix'
NextContinuationToken = True

while NextContinuationToken:
	if NextContinuationToken == True:
		response = client.list_objects_v2(Bucket=bucket,Prefix=prefix)
	else:
		response = client.list_objects_v2(Bucket=bucket,Prefix=prefix,ContinuationToken=NextContinuationToken)
	NextContinuationToken = response['NextContinuationToken']