I have the following code in python:
import os
class suppress_stdout_stderr(object):
'''
A context manager for doing a "deep suppression" of stdout and stderr in
Python, i.e. will suppress all print, even if the print originates in a
compiled C/Fortran sub-function.
This will not suppress raised exceptions, since exceptions are printed
to stderr just before a script exits, and after the context manager has
exited (at least, I think that is why it lets exceptions through).
'''
def __init__(self):
# Open a pair of null files
self.null_fds = [os.open(os.devnull,os.O_RDWR) for x in range(2)]
# Save the actual stdout (1) and stderr (2) file descriptors.
self.save_fds = (os.dup(1), os.dup(2))
def __enter__(self):
# Assign the null pointers to stdout and stderr.
os.dup2(self.null_fds[0],1)
os.dup2(self.null_fds[1],2)
def __exit__(self, *_):
# Re-assign the real stdout/stderr back to (1) and (2)
os.dup2(self.save_fds[0],1)
os.dup2(self.save_fds[1],2)
# Close the null files
os.close(self.null_fds[0])
os.close(self.null_fds[1])
for i in range(10**6):
with suppress_stdout_stderr():
print 'plop'
if i % 50 == 0:
print i
在OSX上,出现了5100错误,错误提示为OSError: [Errno 24] Too many open files
。我想知道为什么会出现这个错误,以及是否有关闭文件描述符的解决方案。我正在寻找一个可以关闭stdout和stderr的上下文管理器的解决方案。
f = open(...); f.close()
。 - Byte Commander