Steven D'Aprano added the comment:
This is a operation precedence issue.
The line:
t0, t1 = t if t is not None else [], []
is parsed as:
(t if t is not None else []), []
so you need brackets around the "else" operand to get the effect you want.
t0, t1 = t if t is not None els
New submission from Wietse Jacobs :
I suspect that I found a bug. If I run the following script:
```
def f(t=None):
t0, t1 = t if t is not None else [], []
return t0, t1
def g(t=None):
if t is None:
t = [], []
t0, t1 = t
return t0, t1
def test():
res_f = f(t=
