你可以尝试更好的方法

import sys

class Logger(object):
    def __init__(self, filename="Default.log"):
        self.terminal = sys.stdout
        self.log = open(filename, "a")

    def write(self, message):
        self.terminal.write(message)
        self.log.write(message)

sys.stdout = Logger("yourlogfilename.txt")
print "Hello world !" # this is should be saved in yourlogfilename.txt

import sys
sys.stdout = open('stdout.txt', 'w')

你可以尝试更好的方法

import sys

class Logger(object):
    def __init__(self, filename="Default.log"):
        self.terminal = sys.stdout
        self.log = open(filename, "a")

    def write(self, message):
        self.terminal.write(message)
        self.log.write(message)

sys.stdout = Logger("yourlogfilename.txt")
print "Hello world !" # this is should be saved in yourlogfilename.txt

正如@jfs提到的，大多数解决方案不能正确处理某些类型的stdout输出，例如来自C扩展的输出。在PyPI上有一个名为wurlitzer的模块负责处理所有这些。您只需要它的sys_pipes上下文管理器。简单易用:

from contextlib import redirect_stdout
import os
from wurlitzer import sys_pipes
        
log = open("test.log", "a")
with redirect_stdout(log), sys_pipes():
    print("print statement")
    os.system("echo echo call")

您需要一个终端多路复用器，比如tmux或GNU屏幕

我很惊讶Ryan Amos对原始问题的一个小评论是唯一一个比其他所有问题都更可取的解决方案，不管蟒蛇的诡计有多聪明，他们得到了多少点赞。根据Ryan的评论，tmux是GNU屏幕的一个很好的替代品。

But the principle is the same: if you ever find yourself wanting to leave a terminal job running while you log-out, head to the cafe for a sandwich, pop to the bathroom, go home (etc) and then later, reconnect to your terminal session from anywhere or any computer as though you'd never been away, terminal multiplexers are the answer. Think of them as VNC or remote desktop for terminal sessions. Anything else is a workaround. As a bonus, when the boss and/or partner comes in and you inadvertently ctrl-w / cmd-w your terminal window instead of your browser window with its dodgy content, you won't have lost the last 18 hours-worth of processing!

用其他语言(例如C)编写的程序必须使用特殊的魔法(称为双分叉)来明确地与终端分离(并防止僵尸进程)。所以，我认为最好的解决办法是模仿他们。

重新执行程序的一个好处是，你可以在命令行上选择重定向，例如/usr/bin/python mycoolscript.py 2>&1 1>/dev/null

查看这篇文章了解更多信息:在创建守护进程时执行双fork的原因是什么?