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?

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?

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!

Python 3.4+中有contextlib.redirect_stdout()函数:

from contextlib import redirect_stdout

with open('help.txt', 'w') as f:
    with redirect_stdout(f):
        print('it now prints to `help.text`')

它类似于:

import sys
from contextlib import contextmanager

@contextmanager
def redirect_stdout(new_target):
    old_target, sys.stdout = sys.stdout, new_target # replace sys.stdout
    try:
        yield new_target # run some code with the replaced stdout
    finally:
        sys.stdout = old_target # restore to the previous value

可以在早期的Python版本中使用。后一个版本是不可重用的。如果需要，它可以成为一个。

它不会在文件描述符级别重定向标准输出，例如:

import os
from contextlib import redirect_stdout

stdout_fd = sys.stdout.fileno()
with open('output.txt', 'w') as f, redirect_stdout(f):
    print('redirected to a file')
    os.write(stdout_fd, b'not redirected')
    os.system('echo this also is not redirected')

B 'not重定向'和'echo this also is not重定向'不会重定向到output.txt文件。

要在文件描述符级别重定向，可以使用os.dup2():

import os
import sys
from contextlib import contextmanager

def fileno(file_or_fd):
    fd = getattr(file_or_fd, 'fileno', lambda: file_or_fd)()
    if not isinstance(fd, int):
        raise ValueError("Expected a file (`.fileno()`) or a file descriptor")
    return fd

@contextmanager
def stdout_redirected(to=os.devnull, stdout=None):
    if stdout is None:
       stdout = sys.stdout

    stdout_fd = fileno(stdout)
    # copy stdout_fd before it is overwritten
    #NOTE: `copied` is inheritable on Windows when duplicating a standard stream
    with os.fdopen(os.dup(stdout_fd), 'wb') as copied: 
        stdout.flush()  # flush library buffers that dup2 knows nothing about
        try:
            os.dup2(fileno(to), stdout_fd)  # $ exec >&to
        except ValueError:  # filename
            with open(to, 'wb') as to_file:
                os.dup2(to_file.fileno(), stdout_fd)  # $ exec > to
        try:
            yield stdout # allow code to be run with the redirected stdout
        finally:
            # restore stdout to its previous value
            #NOTE: dup2 makes stdout_fd inheritable unconditionally
            stdout.flush()
            os.dup2(copied.fileno(), stdout_fd)  # $ exec >&copied

如果使用stdout_redirected()而不是redirect_stdout()，同样的例子现在也可以工作:

import os
import sys

stdout_fd = sys.stdout.fileno()
with open('output.txt', 'w') as f, stdout_redirected(f):
    print('redirected to a file')
    os.write(stdout_fd, b'it is redirected now\n')
    os.system('echo this is also redirected')
print('this is goes back to stdout')

只要stdout_redirect()上下文管理器处于活动状态，以前在stdout上打印的输出现在就会转到output.txt。

注意:stdout.flush()不刷新 Python 3上的C stdio缓冲区，其中I/O直接在read()/write()系统调用上实现。要刷新所有打开的C stdio输出流，如果某些C扩展使用基于stdio的I/O，可以显式调用libc.fflush(None):

try:
    import ctypes
    from ctypes.util import find_library
except ImportError:
    libc = None
else:
    try:
        libc = ctypes.cdll.msvcrt # Windows
    except OSError:
        libc = ctypes.cdll.LoadLibrary(find_library('c'))

def flush(stream):
    try:
        libc.fflush(None)
        stream.flush()
    except (AttributeError, ValueError, IOError):
        pass # unsupported

你可以使用stdout参数重定向其他流，而不仅仅是sys。标准输出，例如，合并sys。Stderr和sys.stdout:

def merged_stderr_stdout():  # $ exec 2>&1
    return stdout_redirected(to=sys.stdout, stdout=sys.stderr)

例子:

from __future__ import print_function
import sys

with merged_stderr_stdout():
     print('this is printed on stdout')
     print('this is also printed on stdout', file=sys.stderr)

注:stdout_redirects()混合缓冲I/O (sys。通常是stdout)和非缓冲I/O(直接对文件描述符进行操作)。注意，可能存在缓冲问题。

要回答这个问题，您的编辑:您可以使用Python -daemon来守护脚本，并使用日志记录模块(如@erikb85所建议的)，而不是打印语句，并仅为您现在使用nohup运行的长时间运行的Python脚本重定向stdout。

以下是Yuda Prawira的回答:

实现flush()和所有文件属性 将其编写为上下文管理器 也捕获stderr

.

import contextlib, sys

@contextlib.contextmanager
def log_print(file):
    # capture all outputs to a log file while still printing it
    class Logger:
        def __init__(self, file):
            self.terminal = sys.stdout
            self.log = file

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

        def __getattr__(self, attr):
            return getattr(self.terminal, attr)

    logger = Logger(file)

    _stdout = sys.stdout
    _stderr = sys.stderr
    sys.stdout = logger
    sys.stderr = logger
    try:
        yield logger.log
    finally:
        sys.stdout = _stdout
        sys.stderr = _stderr


with log_print(open('mylogfile.log', 'w')):
    print('hello world')
    print('hello world on stderr', file=sys.stderr)

# you can capture the output to a string with:
# with log_print(io.StringIO()) as log:
#   ....
#   print('[captured output]', log.getvalue())

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