args_pass_to_func_05.py

# ===================================================================
# Arguments Passed to Function
# ===================================================================
# Python uses a mechanism, which is known as "Call-by-Object",
# sometimes also called "Call by Object Reference" or "Call by
# Sharing". If you pass immutable arguments like integers,
# strings or tuples to a function, the passing acts like
# call-by-value. ... It's different, if we pass mutable arguments.
# ===================================================================

def func(x):
    x[1][2] = 1000
    xx = x[1]
    xx[1] = 'abc'
    print('func  : x = {}'.format(x))
    return

l = [10,20,30]                 # list - mutable

i = (1,l,3)                    # tuple - immutable

print('before: i = {}  {}'.format(i,type(i)))

func(i)

print('after : i = {}  {}'.format(i,type(i)))