[Python-ideas] Where-statement (Proposal for function expressions)

[Gerald Britton]

About return, yield and their ilk in where clauses:

don't do it!

Seriously,  a where clause should be restricted to providing
definitions for the things in the statement for which the where clause
is specified.  Today, we can't do a return (with argument) in a
generator function, which makes sense.  A where clause should not
allow returns or yields or in general actions that explicitly transfer
control beyond the statement.