On 5/8/2014 8:41 AM, Roy Smith wrote:
In article <mailman.9742.1399477705.18130.python-l...@python.org>,
Jerry Hill <malaclyp...@gmail.com> wrote:
thinking of python variables as having two parts -- names and values
-- really can help people who are struggling to learn the language.
There's many levels of learning, and we see them all on this list.
For people who are just learning programming, and are learning Python as
their first language, we need to keep things simple. These are the
people who are still struggling to understand basic concepts such as
algorithms, loops, and the most fundamental data structures. For those
people, talking about variables as a container to hold a value is the
right level of abstraction.
At some point, that model no longer fits reality well enough that it
becomes a barrier to further learning. When I write:
def mutate(x, y):
x = 42
y[0] = 42
x = 4
y = [4]
mutate(x, y)
print x, y
and run it, unless I really understand about name binding and argument
passing, I'm going to be totally befuddled by the result. At that
point, I need to unlearn something I thought I understood, and that's
really hard (en.wikipedia.org/wiki/Principles_of_learning#Primacy).
The "surprising" things can be demonstrated without using functions.
Once assignment statements are mastered, the way argument passing works
can be extrapolated. New programmers will have to further be taught
about shadowing and scopes, while experienced programmers should already
be up and running (until they try to get cute).
Of course everybody has to eventually learn about the special syntax
usable in function definitions and function calls.
--
Neil Cerutti
--
https://mail.python.org/mailman/listinfo/python-list
