如何在没有密码的情况下使用paramiko连接到远程服务器？

我正在用 Python 编写一个脚本，需要连接到remote_server使用 SSH 并移动file from remote_server to host_server。我需要在没有密码的情况下执行此操作，因为它需要适用于任何远程服务器和任何主机服务器用户。

My code:

#get IP and username for remote access
IP = input("Enter host_server IP: ").split()
username = input("Enter username: ").split()
#password = ???????

#create a file on host_server for file
file_a = open(date+"file.txt", "a") #ignore the date variable
file = str(date+"file.txt")

#move file to host_server
import paramiko
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(IP[0], username = user[0], password = password[0])
print "Connected to server."
transfer = ssh.open_sftp()
transfer.get("file.txt", file)
transfer.close()
print "Transfer completed."

问题：有没有办法在脚本中设置公钥而无需访问命令行终端，以便每次脚本运行时都会使用 SSH 设置无密码访问？

ssh.connect()接受一个关键字参数pkey您可以使用它来指定您的私人文件。

#get IP and username for remote access
IP = input("Enter host_server IP: ").split()
username = input("Enter username: ").split()


#create a file on host_server for file
file_a = open(date+"file.txt", "a") #ignore the date variable
file = str(date+"file.txt")
import paramiko
import os
privatekeyfile = os.path.expanduser('~/.ssh/id_rsa')
mykey = paramiko.RSAKey.from_private_key_file(privatekeyfile)
ssh.connect(IP[0], username = user[0], pkey = mykey)