[Python] Can I get the offset to the underlying object from a memoryview? (Why not?) Is there...

I'm implementing a parser for a binary (image) file format. memoryview seems to be an almost perfect solution for this: The parser class keeps the data in a bytes object and passes sliced memoryviews to code that parses substructures. Sometimes those substructures contain offsets relative to the entire file; this is handily supported by the underlying object being a field of the memoryview, so I can always get a memoryview to any file offset. All my memoryviews are contiguous.

Now, I have a function that returns a bunch of these contiguous memoryviews which correspond to all the image data in the image file (as opposed to the metadata), and I would like to determine which ranges of the underlying bytes object—or, equivalently, the image file—they correspond to. In other words, I would like to extract from the memoryview information corresponding to "it is a view of underlying_bytes[12:100]".

It seems to me that the memoryviews necessarily have internally sufficient information to compute the start and end offsets in the underlying object that they correspond to. However, I can find no method that would help me access this information.

Is there such a method? Would such a method on memoryview be a bad or impossible idea for some reason? Is there a convenient alternative to memoryview that would allow me to do this?

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