[Tutor] am I missing another simpler structure?
op73418 at mail.telepac.pt
Thu Dec 16 15:30:22 CET 2004
Loptr Chaote wrote:
> On Wed, 15 Dec 2004 19:58:56 -0500, Brian van den Broek
> 1) Every operation has a return value [unless purposefully left out]
> This includes, but is not limited to; mathematical operations (of
> course), variable assignment, compare blocks, etc..
A small correction: every function has a return value. If left out (that
is, no return statement) then it returns None. E.g.
>>> def noret():
... 2 + 2
>>> print noret()
Statements have no return value, e.g.
>>> a = 1
>>> print a = 1
Traceback ( File "<interactive input>", line 1
print a = 1
SyntaxError: invalid syntax
Like the above shows, assigment has no return value -- it's a statement.
This is precisely the distinction between a *statement* (like
assignment) and an expression (like a function call). Python has this
distinction like most languages. A language like Scheme doesn't since
everything is an expression.
With my best regards,
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