On Fri, Apr 8, 2011 at 10:26 AM, candide <candide at free.invalid> wrote: >>>> x=42 >>>> bool(x=5) > True >>>>>>> but _expression_ : >> x=42 >>> has no value. "x=42" is an assignment statement, not an expression. In "bool(x=5)", "x=5" is also not an expression. It's passing the expression "5" in as the parameter x, using a keyword argument.