Python vs C for a mail server

[Magnus Lycka]

Randall Parker wrote:
> I return objects in Python and in C++. In C++ I can see what their
> types are right on the m method signature. In Python I've got to write
> a comment on the line above it. 

Ouch! Don't do that! As you've noticed, it's not very maintainable.

First of all, if you want to use Python well, embrace it's dynamic
nature, don't try to restrain it! It takes some time to let go of
the static thinking if one is used to it, but try. Just as lots of
programming guidelines (e.g. Parna's Principle and The Law of
Demeter) tells us that we should try to know and depend as little
as possible on the details in other pieces of code, the duck typing
behaviour in Python extends this one step further, to types.

Without proper tests, this might cause more problems than it solves,
but there is no excuse for not having proper automated tests for
software you develop in the 21st century!!!

You *don't* write an unmaintainable comment about what return
type to expect, you write unit tests that shows you how to use
each API that you implement. You run these tests often, fix them
as soon as they break, and you encourage their use as
documentation which describes through examples how to use you
APIs. (Sorry about the imperative tone. It's your life after
all, but don't blame Python for not fitting your style of
development.)

You should do that for statically typed languages as well. Knowing
that you got the correct type back gives you no assurance that
you got the right value!