Unless I'm completely mistaken, the order of precedence is preserved in both variants:

# These are equivalent
delta = timestamp or time.time() - OFFSET
delta = (timestamp or time.time()) - OFFSET

When the provided timestamp is based on epoch 1970, OFFSET needs to be subtracted to get it to canopen January 1, 1984 epoch.

Unless I'm completely mistaken, the order of precedence is preserved in both variants:

# These are equivalent
delta = timestamp or time.time() - OFFSET
delta = (timestamp or time.time()) - OFFSET

When the provided timestamp is based on epoch 1970, OFFSET needs to be subtracted to get it to canopen January 1, 1984 epoch.

These expressions are not the same, - comes before or in operator precedence: https://docs.python.org/3/reference/expressions.html#operator-precedence

Correct that OFFSET should be subtracted from either timestamp argument or time.time() for a time in CANopen epoch, but the current expression doesn't do that.

Yeah, I see it now

>>> 0 or 1 - 5
-4
>>> (0 or 1) - 5
-4
>>> None or 1 - 5
-4
>>> (None or 1) - 5
-4
>>> 1 or 2 - 5
1
>>> (1 or 2) - 5
-4