<p>IPython有自己的<a href="https://github.com/ipython/ipython/blob/rel-0.13.1/IPython/utils/io.py#L359" rel="noreferrer">capturing stdout/err</a>上下文管理器,但它不重定向到文件,而是重定向到一个对象:</p>
<pre><code>from IPython.utils import io
with io.capture_output() as captured:
%run my_script.py
print captured.stdout # prints stdout from your script
</code></pre>
<p>这个功能在<code>%%capture</code>单元魔术中公开,如<a href="http://nbviewer.ipython.org/urls/raw.github.com/ipython/ipython/master/examples/notebooks/Cell%20Magics.ipynb" rel="noreferrer">Cell Magics example notebook</a>所示。</p>
<p>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:</p>
<pre><code>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
</code></pre>
<p>你可以用它来调用:</p>
<pre><code>with redirect_output("my_output.txt"):
%run my_script.py
</code></pre>