[Python-ideas] Multi Statement Lambdas

Chris Angelico rosuav at gmail.com
Sun Oct 21 19:25:19 EDT 2018

On Mon, Oct 22, 2018 at 10:16 AM Terry Reedy <tjreedy at udel.edu> wrote:
> On 10/21/2018 12:28 PM, Andreas Winschu wrote
> > A def function has to be named.
> In general, this is a good thing.  It often improves tracebacks.
> Perhaps more importantly, name facilitate testing and mocking.
> > Wheres a lambda expression can be passed anonymously to any other
> > function as an argument.
> Except for relatively trivial expressions, this is a bad thing.  All
> functions created from lambda expressions get the same pseudo-name
> '<lambda>'.  This can make tracebacks worse.  Perhaps more importantly,
> proper testing may become harder.

The same considerations bite comprehensions, too, but we don't
discourage their use. So I don't think this should be a killer - not
on its own, anyhow.

I do not currently support any proposed syntax for multi-statement
lambda functions, mainly because they've all been ugly. But maybe
there'll be one, somewhere, some day, that makes sense.


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