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pythonmathhashfloating-pointpi

Why does Python's hash of infinity have the digits of π?

The hash of infinity in Python has digits matching pi:

>>> inf = float('inf')
>>> hash(inf)
314159
>>> int(math.pi*1e5)
314159

Is that just a coincidence or is it intentional?

Solution

  • _PyHASH_INF is defined as a constant equal to 314159.

    I can't find any discussion about this, or comments giving a reason. I think it was chosen more or less arbitrarily. I imagine that as long as they don't use the same meaningful value for other hashes, it shouldn't matter.