What is a function parameter =[] for?

[Marko Rauhamaa]

Steven D'Aprano <steve at pearwood.info>:

> Really? Astonishing. To me, the Ackermann's function is a
> straight-forward, simple example.

I must admit I have not once in my life written an implementation of the
Ackermann function.

> Whereas this initiate_query example is the opposite of
> straight-forward. It involves a database, which means side-effects.

Again, I must hang my head and confess that I have written quite many
functions with side effects.

> (If lambda is exotic to you because your personal experience happens
> to have avoided that area, databases are equally exotic to me for the
> same reason.

Lambdas are less exotic than layman programmers might think. You may
never need a lambda in Python but you will need to master closures and
inner classes.


Marko