Patched code sample

import logging
import re

class SensitiveDataFilter(logging.Filter):
    """
    A logging filter that redacts sensitive information like Redis passwords.
    """

    def __init__(self, sensitive_patterns):
        """
        Initializes the filter with a list of regular expression patterns
        to match sensitive information.
        """
        super().__init__()
        self.sensitive_patterns = sensitive_patterns

    def filter(self, record):
        """
        Filters the log record, redacting any matching sensitive information.
        """
        message = record.getMessage()
        for pattern in self.sensitive_patterns:
            message = re.sub(pattern, "<redacted>", message)
        record.msg = message
        return True


def configure_logging(redis_password=None):
    """
    Configures logging with a filter to redact the Redis password if present.
    """
    logger = logging.getLogger()
    logger.setLevel(logging.INFO)  # Or your desired log level
    handler = logging.StreamHandler() # Or your desired handler (file, etc.)
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    handler.setFormatter(formatter)
    logger.addHandler(handler)

    sensitive_patterns = []
    if redis_password:
        # Create a regex pattern to match the Redis password.  Using re.escape is important!
        # It handles special characters in the password to prevent regex injection issues.
        sensitive_patterns.append(re.compile(re.escape(redis_password)))
        sensitive_patterns.append(re.compile(r'redis:\/\/.*:' + re.escape(redis_password) + r'@')) #matches connection strings as well

    if sensitive_patterns:
        filter = SensitiveDataFilter(sensitive_patterns)
        logger.addFilter(filter)

    return logger


if __name__ == '__main__':
    # Example Usage
    redis_pw = "my_secret_redis_password!@#$"
    log = configure_logging(redis_pw)

    log.info(f"Connecting to Redis with password: {redis_pw}")
    log.info(f"Redis connection string: redis://user:{redis_pw}@redis_host:6379")
    log.info("This is a normal log message without sensitive data.")

    # Showcasing a message without the password provided during configuration
    log2 = configure_logging()
    log2.info(f"Explicitly logging the password {redis_pw} - THIS IS BAD") # This WILL get logged if not configured