default values of function parameters

[David Isaac]

Alan Isaac wrote:

Default parameter values are
evaluated once when the function definition is
executed. Where are they stored? ... Where is this documented?

Forgive any poor phrasing: I'm not a computer science type.
At http://www.network-theory.co.uk/docs/pytut/tut_26.html we read:
"The execution of a function introduces a new symbol table
used for the local variables of the function. More precisely,
all variable assignments in a function store the value in the local
symbol table; whereas variable references first look in the local
symbol table, then in the global symbol table, and then in the table of
built-in names."

But the default values of function parameters seem rather like a static
attributes of a class.
Is that a good way to think of them?
If so, are they somehow accessible?
How? Under what name?

Thanks,
Alan Isaac

[Terry Reedy]

"David Isaac" <ai*****@verizon.net> wrote in message
news:piPoe.8518$ld3.1868@trnddc04...

But the default values of function parameters seem rather like a static
attributes of a class.
Is that a good way to think of them?
If you think of a function as defining a subclass of execution instances,
with __init__ inherited from the superclass, then that is a possible way to
think of them. Goodness depends on your meaning of goodness ;-). Does it
help you write and use Python functions acurately?
If so, are they somehow accessible?
How? Under what name?

This is implementation specific. For CPython, the interactive interpreter
is your friend. Learn to use it!

def f(): pass .... dir(f)

['__call__', '__class__', '__delattr__', '__dict__', '__doc__', '__get__',
'__ge
tattribute__', '__hash__', '__init__', '__name__', '__new__', '__reduce__',
'__r
epr__', '__setattr__', '__str__', 'func_closure', 'func_code',
'func_defaults',
'func_dict', 'func_doc', 'func_globals', 'func_name']

Now give f some parameters with defaults and print f.func_defaults.

Terry J. Reedy