call-by-reference function parameters

Question

Given a function:

def A(a, b, c):
    a *= 2
    b *= 4
    c *= 8
    return a+b+c

How can I set the \'c\' var to be called-by-reference,

Answer 1

You can do this if c is a list:

c = [2]
def A(a, b, c):
    a *= 2
    b *= 4
    c[0] *= 8
    return a+b+c[0]
print c  # gives [16]