Steve Stagg <[email protected]> added the comment:
To be super pedantic, as per my understanding of:
"6.11 ... The expression x and y first evaluates x; if x is false, its value is
returned; otherwise, y is evaluated and the resulting value is returned."
The only corner that was previously cut is that in this statement:
if a and b:
...
The evalution should be roughly equivalent to:
bool(a) if bool(a) else bool(b) # <- where bool(b) is never called
instead it's more like:
_x if _x := bool(a) else bool(b) # <- where bool(b) is never called
so, the runtime is eliding a repeated call to bool(a).
This obviously causes problems if bool(a) has per-call side-effects, but this
seems to me like a reasonable corner to cut.
Totally eliding the if clause feels to me (subjectively) like a much more risky
proposition, and perhaps one that should be documented if kept in?
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Python tracker <[email protected]>
<https://bugs.python.org/issue42899>
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