def f(a, b):
    print(id(a))
    print(id(b))

p = 1
q = [1, 2, 3]
print(id(p))
print(id(q))
f(p, q)

print()

def f(liste):
    liste[0] = 42
    liste += [5, 6, 7, 8, 9]

zahlen = [1, 2, 3, 4]
print(zahlen)
f(zahlen)
print(zahlen)

zahlen = [1, 2, 3, 4]
print(zahlen)
f(zahlen[:])        # Koie übergeben (Kopie durch Slicing)
print(zahlen)

print()

def g(a=[1, 2, 3]):
    a += [4, 5]
    print(a)

g()     # [1, 2, 3, 4, 5]
g()     # [1, 2, 3, 4, 5, 4, 5]
g()     # [1, 2, 3, 4, 5, 4, 5, 4, 5]
g()     # [1, 2, 3, 4, 5, 4, 5, 4, 5, 4, 5]

print()

def h(a=None):
    if a is None:
        a = [1, 2, 3]
    a += [4, 5]
    print(a)

h()     # [1, 2, 3, 4, 5]
h()     # [1, 2, 3, 4, 5]
h()     # [1, 2, 3, 4, 5]
h()     # [1, 2, 3, 4, 5]