On Tue, Jan 5, 2016, at 16:04, Guido van Rossum wrote:
One problem with stat() caching is that Path objects are considered immutable, and two Path objects referring to the same path are completely interchangeable. For example, {pathlib.Path('/a'), pathlib.Path('/a')} is a set of length 1: {PosixPath('/a')}. But if we had e.g. Path('/a', cache_stat=True), the behavior of two instances of that object might be observably different (if they were instantiated at times when the contents of the filesystem was different). So maybe stat-caching Path instances should be considered unequal, or perhaps unhashable. Or perhaps they should only be considered equal if their stat() values are actually equal (i.e. if the file's stat() info didn't change).
What about a global cache?