Question

Have a method with the following signature:

def foo(self, bar, *uks):
    return other_method(..., uks)

Normally this is called as:

instance.foo(1234, a, b, c, d)

However in some cases I need to do something like this:

p = [a, b, c, d]
instance.foo(1234, p)

At the receiving end this does not work, because other_method sees *args being made up of a single list object instead of simply a [a, b, c, d] list construct. If I type the method as:

def foo(self, bar, uks = []):
    return other_method(..., uks)

It works, but then I’m forced to do this every time:

instance.foo(1234, [a, b, c, d])

It’s not a huge deal I guess, but I just want to know if I’m missing some more pythonic way of doing this?

Thanks!

Answer 1

Python supports unpacking of argument lists to handle exactly this situation. The two following calls are equivalent:

Regular call:

instance.foo(1234, a, b, c, d)

Argument list expansion:

p = [a, b, c, d]
instance.foo(1234, *p)