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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def postproc(self):
 """Remove sensitive keys and passwords from YAML files."""

        secrets_files = [
            "/etc/openstack_deploy/user_secrets.yml",
            "/etc/rpc_deploy/user_secrets.yml"
        ]
        regexp = r"(?m)^\s*#*([\w_]*:\s*).*"
        for secrets_file in secrets_files:
            self.do_path_regex_sub(
                secrets_file,
                regexp,
                r"\1*********")