Close failed in file object destructor: sys.excepthook is missing lost sys.stderr

Question

Problem :

I have attempted to reproduce my problem described below under only Python 2.7.3.

The most reliable way that I found to elicit my problem in the question is to pipe my output of the next test script through the use of  : (under bash):

try:

    for m in range(40):

        print m

except:

    pass

The error message received as below :

% mypython testscript.py | :

close failed in file object destructor:

sys.excepthook is missing

lost sys.stderr

As the test script clearly shows that the error cannot be trapped with the try-except.

My question is as below:

How can I modify my test script above to avoid facing the error message whenmy script is run as shown above (under  the Unix/bash)?

Answer 1

When you try to pipe the output of one program into the another, the output produced by the first  writing program gets backed up in the buffer, and it waits for your reading program to request that data from your buffer. As long as your buffer is nonempty, any attempt to made to close your writing file object is supposed to fail with the error. This is the root cause behind the messages you are expearencing.

The specific code that is triggering the error is in your C language implementation of the Python, which explains why you can not catch the error with the try/except block: as it runs after your contents of the script has finished the processing.