Exceptions when closing a file

[Ross Ridge]

Steven D'Aprano  <steve at REMOVE.THIS.cybersource.com.au> wrote:
>Closing a file can (I believe) raise an exception. Is that documented
>anywhere? 

In a catch-all statement for file objects: "When a file operation fails
for an I/O-related reason, the exception IOError is raised."  The fact
that close() is a file operation that might fail is revealed by "file
objects are implemented using C's stdio package" and the fact the C's
fclose() function can fail.

> Is IOError the only exception it can raise?

I assume it can raise the exceptions MemoryError and KeyboardInterupt,
which just about any Python operation can raise.

>Out of curiosity, is there a simple way to demonstrate close() raising an
>exception that doesn't involve messing about with disk quotas? 

Something like the following should work:

	f = file("/dev/null", "r")
	os.close(f.fileno)
	f.close()

Normally however, you can expect file method close() to fail for all
the same reasons you would expect write() to fail.

					Ross Ridge

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