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Read Watches in Python
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dutc = Don't Use This Code (!!)


  • Python 3.5 or higher
  • Linux or OS X
  • need build toolchain (prob. need gcc)

Read Watches in Python

>>> import rwatch # enable functionality
>>> from sys import setrwatch, getrwatch
>>> x, y, z = object(), object(), object()
>>> def view(frame, obj):
...     print(frame, obj)
...     return obj
>>> setrwatch({id(x): view, id(y): view})
>>> getrwatch()
{139825758638208: <function view at 0x7f2bb89a59d8>, 139825758638224: <function view at 0x7f2bb89a59d8>}
>>> x
<frame object at 0x7f2bb8ad9ba8> <object object at 0x7f2bb8ac9080>
<object object at 0x7f2bb8ac9080>
>>> y
<frame object at 0x7f2bb8ad9d48> <object object at 0x7f2bb8ac9090>
<object object at 0x7f2bb8ac9090>
>>> z
<object object at 0x7f2bb8ac90a0>


  • read watches are a very useful tool for debugging
  • it's actually very useful for a language to have a runtime
  • there are some hidden equivalencies between, e.g., read watches and perfect proxy objects
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