unpack a fixed number of elements from iterables of arbitrary length

example.py

# example.py
#
# Unpacking of tagged tuples of varying sizes

records = [
     ('foo', 1, 2),
     ('bar', 'hello'),
     ('foo', 3, 4),
]

def do_foo(x,y):
    print('foo', x, y)

def do_bar(s):
    print('bar', s)

for tag, *args in records:
    if tag == 'foo':
        do_foo(*args)
    elif tag == 'bar':
        do_bar(*args)