IPython：将 Python 脚本的输出重定向到文件（如 bash >）
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IPython: redirecting output of a Python script to a file (like bash >)
提问by wwwilliam
I have a Python script that I want to run in IPython. I want to redirect (write) the output to a file, similar to:
我有一个要在 IPython 中运行的 Python 脚本。我想将输出重定向（写入）到一个文件，类似于：
python my_script.py > my_output.txt
How do I do this when I run the script in IPython, i.e. like execfile('my_script.py')
当我在 IPython 中运行脚本时，我该怎么做，比如 execfile('my_script.py')
There is an older pagedescribing a function that could be written to do this, but I believe that there is now a built-in way to do this that I just can't find.
有一个较旧的页面描述了可以编写来执行此操作的函数，但我相信现在有一种内置的方法可以执行此操作，但我找不到。
采纳答案by minrk
IPython has its own context manager for capturing stdout/err, but it doesn't redirect to files, it redirects to an object:
IPython 有自己的上下文管理器用于捕获 stdout/err，但它不会重定向到文件，而是重定向到一个对象：
from IPython.utils import io
with io.capture_output() as captured:
%run my_script.py
print captured.stdout # prints stdout from your script
And this functionality is exposed in a %%capturecell-magic, as illustrated in the Cell Magics example notebook.
并且此功能在%%capturecell-magic 中公开，如Cell Magics 示例笔记本 中所示。
It's a simple context manager, so you can write your own version that would redirect to files:
这是一个简单的上下文管理器，因此您可以编写自己的版本来重定向到文件：
class redirect_output(object):
"""context manager for reditrecting stdout/err to files"""
def __init__(self, stdout='', stderr=''):
self.stdout = stdout
self.stderr = stderr
def __enter__(self):
self.sys_stdout = sys.stdout
self.sys_stderr = sys.stderr
if self.stdout:
sys.stdout = open(self.stdout, 'w')
if self.stderr:
if self.stderr == self.stdout:
sys.stderr = sys.stdout
else:
sys.stderr = open(self.stderr, 'w')
def __exit__(self, exc_type, exc_value, traceback):
sys.stdout = self.sys_stdout
sys.stderr = self.sys_stderr
which you would invoke with:
你会用它来调用：
with redirect_output("my_output.txt"):
%run my_script.py
回答by Silas Ray
There's the hacky way of overwriting sys.stdoutand sys.stderrwith a file object, but that's really not a good way to go about it. Really, if you want to control where the output goes from inside python, you need to implement some sort of logging and/or output handling system that you can configure via the command line or function arguments instead of using printstatements.
有一种覆盖sys.stdout和sys.stderr文件对象的hacky方式，但这确实不是一个好方法。真的，如果你想控制 python 内部输出的去向，你需要实现某种日志记录和/或输出处理系统，你可以通过命令行或函数参数而不是使用print语句来配置它。
回答by Mookayama
It seems a lot of code.... My solution. redirect output of ipython script into a csv or text file like sqlplus spoolwonder there is an easy way like oracle sqlplus spool command..?
似乎很多代码....我的解决方案。 将 ipython 脚本的输出重定向到 csv 或文本文件，如 sqlplus spool想知道有没有像 oracle sqlplus spool 命令这样的简单方法..？
回答by eiffel
Writing a script seemed overkill for me, as I just wanted something simple to look at a lot of text contained in a variable while working in IPython. This is what worked for me:
编写脚本对我来说似乎有点过分了，因为我只是想要一些简单的东西来在 IPython 中工作时查看变量中包含的大量文本。这对我有用：
%store VARIABLE >> file.txt(appends)
%store VARIABLE > file.txt(overwrites)
%store VARIABLE >> file.txt（附加）
%store VARIABLE > file.txt（覆盖）
回答by Petteri Nevavuori
While this an old question, I found this and the answers as I was facing a similar problem.
虽然这是一个老问题，但当我面临类似问题时，我发现了这个问题和答案。
The solution I found after sifting through IPython Cell magics documentationis actually fairly simple. At the most basic the solution is to assign the output of the command to a variable.
我在筛选IPython Cell magics 文档后找到的解决方案实际上相当简单。最基本的解决方案是将命令的输出分配给一个变量。
This simple two-cell example shows how to do that. In the first Notebook cell we define the Python script with some output to stdoutmaking use of the %%writefilecell magic.
这个简单的两格示例展示了如何做到这一点。在第一个 Notebook 单元格中，我们定义了 Python 脚本和一些输出以stdout利用%%writefile单元格魔法。
%%writefile output.py
print("This is the output that is supposed to go to a file")
Then we run that script like it was run from a shell using the !operator.
然后我们运行该脚本，就像使用!操作符从 shell 运行一样。
output = !python output.py
print(output)
>>> ['This is the output that is supposed to go to a file']
Then you can easily make use of the %storemagic to persist the output.
然后你可以轻松地利用%store魔法来持久化输出。
%store output > output.log
Notice however that the output of the command is persisted as a list of lines. You might want to call "\n".join(output)prior storing the output.
但是请注意，命令的输出作为行列表持久化。您可能希望"\n".join(output)在存储输出之前调用。
回答by Raful Chizkiyahu
use this code to save the output to file
使用此代码将输出保存到文件
import time
from threading import Thread
import sys
#write the stdout to file
def log():
#for stop the thread
global run
while (run):
try:
global out
text = str(sys.stdout.getvalue())
with open("out.txt", 'w') as f:
f.write(text)
finally:
time.sleep(1)
%%capture out
run = True
print("start")
process = Thread(target=log, args=[]).start()
# do some work
for i in range(10, 1000):
print(i)
time.sleep(1)
run= False
process.join()
It is useful to use a text editor that tracer changes the file and suggest reloading the file like notepad++
使用跟踪器更改文件并建议重新加载文件（如记事本++）的文本编辑器很有用
