using a try/except in a conditional expression

[ndc85430]

It still sounds like passing in the test by means of a function does exactly what you want. For example:

>>> def is_valid(f):
...     try:
...             return f()
...     except:
...             return False
... 
>>> def always_true():
...     return True
... 
>>> def always_throws():
...     raise Exception()
... 
>>> is_valid(always_true)
True
>>> is_valid(always_throws)
False
>>> 

(I didn't have the time to come up with a less contrived example, but hopefully you get the idea).