[Python-ideas] why not try without except?

Ben Finney ben+python at benfinney.id.au
Sat Apr 25 11:12:11 CEST 2009

spir <denis.spir at free.fr> writes:

> Actually, this shows that 'try' alone can be considered analog to 'if'
> without 'else' clause

And without a condition, or a branch. Remember that ‘if’ introduces a
branch point, whereas ‘try’ does not.

> needed when the condition may raise an exception.

But there *is* no condition in a ‘try’ statement.

If what you mean is “when the suite introduced by ‘try:’ may raise an
exception”, that's true of just about every interesting statement in
Python: an exception might be raised at any point.

> Both express an optional action.

No. The suite that follows ‘try’ will be executed, just as surely as a
suite *not* enclosed in ‘try’.

> This could be written more directly, because we do not need the condition:
>    ? <do_something>
>    option <do_something>
> with the meaning: "Try & do this, but if there's an exception just let
>    it down."

What does “let it down” mean?

If you mean “if there's an exception raised, just let it propagate up”,
that's what happens *without* a ‘try’. So I can only assume you mean
something different.

I don't understand the behaviour you describe. Perhaps if you would
explain what you think the difference should be between:


versus this:


How should the behaviour differ?

 \      “It takes a big man to cry, but it takes a bigger man to laugh |
  `\                                        at that man.” —Jack Handey |
_o__)                                                                  |
Ben Finney

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