Load to DynamoDB from a CSV

csv_to_dynamodb.py

import sys
import csv
import boto3

dynamodb = boto3.resource('dynamodb')

def main():

    if len(sys.argv) != 3:
        print("Usage: csv_to_dynamodb.py tableName filename")

    tableName = sys.argv[1]
    filename = sys.argv[2]

    csvfile = open(filename)

    batch_size = 100
    batch = []

    for row in csv.DictReader(csvfile):

        deletes = []

        for key in row:
            if row[key] == "null" or row[key] == "":
                deletes.append(key)
    
        for key in deletes:
            print('delete', key)
            del row[key]

        if len(batch) >= batch_size:
            write_to_dynamo(tableName, batch)
            batch.clear()

        batch.append(row)

    if batch:
        write_to_dynamo(tableName, batch)

    return print("Done")

def write_to_dynamo(tableName, rows):
    table = dynamodb.Table(tableName)
    with table.batch_writer() as batch:
        for row in rows:
            batch.put_item(row)

main()