Python syntax in Lisp and Scheme

[David Mertz]

|> Isn't it true though that the lambda can only contain a single
|> expression and no statements?  That seems to limit closures somewhat.

David Eppstein <eppstein at ics.uci.edu> wrote previously:
|It limits lambdas.  It doesn't limit named functions.  Unlike lisp, a
|Python function definition can be nested within a function call, and the
|inner function can access variables in the outer function's closure.

I don't really know Lisp, so I could be wrong.  But my understanding is
that CL has a 'let' special form that works fine within a function
definition.  In particular, you should be able to define inner functions
by binding a name to a lambda, using 'let'.

So there's nothing really special about the fact that Python (or
Haskell, ML, etc) can nest function definition.  Of course, Haskell's
'let' and 'where' are quite wonderful... even better, syntaxwise, than
Python's nested 'def's.

Yours, David...

P.S. On the prior poster's misunderstanding:  Lambdas in Python are
actually completely general.  There is nothing you cannot express using
a single expression, even side effects--it just gets ugly doing it.
Basically, just like in CL, a list or tuple is a single expression, and
it evaluates its elements in predictable left-to-right order... you can
work out the rest of the ugly details from that fact.  Or you can look
at my articles on "FP in Python"--however, my intent in those is NOT to
enable obfuscated Python, but to point to actual useful techniques.
It's a fine line though.

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