Python unclosed resource: is it safe to delete the file?

Question

Googled my way around this issue, but didn\'t find any solutions. I\'m running Python 3.3 with Eclipse and PyDev plugin, and when I run any Python project, I get the followi

Answer 1

This ResourceWarning means that you opened a file, used it, but then forgot to close the file. Python closes it for you when it notices that the file object is dead, but this only occurs after some unknown time has elapsed. Thus in recent versions, Python also prints a ResourceWarning when it does that. It is a way for you to quickly identify where the unclosed files are, and properly close them. It might be important on some platforms which cannot have more than N files opened at the same time (e.g. 1024). Also, specifically on Windows, you cannot do some operations with a file if it's still open (e.g. deleting it).

In this case, the line in the file update_checker.py needs to be fixed to say:

with open(filename, 'rb') as f:   # will close() when we leave this block
    permacache = pickle.load(f)