[Python-Dev] Use function names instead of functions for os.supports_dir_fd? (original) (raw)

Steven D'Aprano steve at pearwood.info
Wed Jul 18 01:45:28 CEST 2012

Victor Stinner wrote:

Hi,

Python 3.3 introduced os.supportsdirfd to check if some os functions do accept a file descriptor instead of a path. The problem is that os.supportsdirfd is a list of functions, not a list of function names. If os functions are monkey patched, you cannot test anymore if a function supports file descriptor.

One of the dangers of monkey-patching.

Monkey patching is a common practice in Python. testos.py replaces os.exec*() functions temporary for example.

Perhaps for testing, but I don't think monkey-patching is common in production code. Perhaps you are thinking of Ruby :)

It's also inconsistent with the new time.getclockinfo() function which expects the name of a time function, not the function directly.

Since functions are first-class objects in Python, and people should be used to passing functions around as parameters, perhaps it is better to say that get_clock_info is inconsistent with supports_dir_fd.

Personally, I prefer passing function objects rather than names, since the name of the function shouldn't matter. But since I recognise that other people may think differently, I would probably support passing both the name or the function object itself.

-- Steven

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