What is a function parameter =[] for?

[John Gordon]

In <d9045bdd-a5d4-4c5c-9fd3-3d54f6b50862 at googlegroups.com> fl <rxjwg98 at gmail.com> writes:

> Hi,

> I have tried the below function and find that it can remember the previous
> setting value to 'val'. I think the second parameter has something on this 
> effect, but I don't know the name and function of '=[]' in this application.

> Could you explain a little to me?
> Thanks,

> def eList(val, list0=[]):
>     list0.append(val)
>     return list0
> list1 = eList(12)
> list1 = eList('a')

That is a default parameter.  If eList() is called without an argument for
list0, it will use [] as the default value.

-- 
John Gordon                   A is for Amy, who fell down the stairs
gordon at panix.com              B is for Basil, assaulted by bears
                                -- Edward Gorey, "The Gashlycrumb Tinies"