[Python-Dev] Pre-PEP: with syntax (was: New syntax threads -- summary wanted) (original) (raw)

Samuele Pedroni pedronis@bluewin.ch
Mon, 10 Feb 2003 16:36:49 +0100

'with' [ var '=' ] expr ':' suite

This statement is defined as being equivalent to the following sequence of statements: var = expr if hasattr(var, "enter"): var.enter() try: suite finally: if hasattr(var, "exit"): var.exit() If the variable is omitted, an unnamed object is allocated on the stack. In that case, the suite has no access to the unnamed object.

I would not really depend when var is specified, that its binding is not modified in suite, I would store expr result away and use that:

var = _secret = expr

... rest of impl uses _secret not var ...

Less fragile.

regards