After I spent long time. I reach to this solution and hope the others who face this problem can take this solution
import paramiko
import os
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(hostname='xxxxxxxxxxx', username='xxxxxxxxx', password='xxxxxxxxx', port='22')
sftp_client = ssh.open_sftp()
sftp_client.chdir('/home/abow/nc_files')
for file in sftp_client.listdir(sftp_client.getcwd()):
print(file)
sftp_client.close()
ssh.close()