Loop-and-a-half (Re: Curious assignment behaviour)

[Huaiyu Zhu]

On Sat, 13 Oct 2001 10:59:38 +0200, Alex Martelli <aleax at aleax.it> wrote:
>Your approach is indeed far more general -- I just showed somewhat-clunky 
>syntax that has the advantage of working right now (and ever since the Dawn 
>of Python) when one is transliterating code from other languages (I 
>wouldn't use it in code meant to be idiomatically Pythonic, or Pythonically 
>idiomatic).  However, the ability to have arbitrary statements as part of 
>an "expression" may be TOO general for comfort -- right now I can rely on 
>the fact that an expression can never rebind my local variables (and this 
>for example makes eval usable where exec might not be), the generalization 
>would take such guarantees away.  A much more wary look at the trade-offs 
>is therefore surely warranted.

Agreed generally.  A clarification, though: the proposal does not allow
statements in expressions; it allows statements _between_ conditional
keywords and the corresponding expressions, like

while [ <statements> ; ] <expression> :  <suite>
if [ <statements> ; ] <expression> :  <suite>

The distinction between expression and statements is not diminished.

Huaiyu