dynamo-update.py

update_expression, update_expression_names, update_values = generate_update(item)

resp = table.update_item(
    Key=key,
    UpdateExpression=update_expression,
    ExpressionAttributeNames=update_expression_names,
    ExpressionAttributeValues=update_values)

print(resp)

def generate_update(item):
    update_expression = ["#{}=:{}".format(k,k) for k in item]
    update_expression = "set " + ', '.join(update_expression)
    update_expression_names = {"#{}".format(k):k for k in item}
    update_values = {":{}".format(k):item[k] for k in item}
    return update_expression, update_expression_names, update_values