Disable boto logging without modifying the boto files

You could try

import logging
logging.getLogger('boto').setLevel(logging.CRITICAL)

which will suppress all (other than CRITICAL) errors.

Boto uses logging configuration files (e.g. /etc/boto.cfg, ~/.boto) so see if you can configure it to your needs that way.

The set_file_logger call simply adds a user-defined file to the logging setup, so you can't use that to turn logging off.

I move the boto3 answer from the comments (namely charneykaye and gene_wood) to a proper answer:

import logging

logger = logging.getLogger()
logger.addHandler(logging.StreamHandler()) # Writes to console
logger.setLevel(logging.DEBUG)
logging.getLogger('boto3').setLevel(logging.CRITICAL)
logging.getLogger('botocore').setLevel(logging.CRITICAL)
logging.getLogger('s3transfer').setLevel(logging.CRITICAL)
logging.getLogger('urllib3').setLevel(logging.CRITICAL)

import boto3

s3 = boto3.resource('s3')

for bucket in s3.buckets.all():
    print(bucket.name)

To get all the loggers follow the response from leobarcellos:

import logging
loggers_dict = logging.Logger.manager.loggerDict