python中将标准输出重定向到null

import os

print("will run")


null_fds = [os.open(os.devnull, os.O_RDWR) for x in range(2)]
# save the current file descriptors to a tuple
save = os.dup(1), os.dup(2)
# put /dev/null fds on 1 and 2
os.dup2(null_fds[0], 1)
os.dup2(null_fds[1], 2)

# *** run the function ***
print("print inside")

# restore file descriptors so I can print the results
os.dup2(save[0], 1)
os.dup2(save[1], 2)
# close the temporary fds
os.close(null_fds[0])
os.close(null_fds[1])

print("done!")
```  


运行后输出的结果为: