# sideEffects.py
# CS 251 Lesson 6
# Studies in the side effects of different Python statements

# First we'll play with some integers
a = 10
b = a
b = 20

print("### TEST 1 ###")
print(a, b)

# Now we'll look at function scope
def f(x):
    a = 4
    x += 1
    print("In f:    ", a, x)

print("\n### TEST 2 ###")
print("Before f:", a, b)
f(b)
print("After f: ", a, b)

# How could we change a?
def g():
    global a
    a += 1
    print("In g:  a=", a)

print("\n### TEST 3 ###")
print("Before g:", a, b)
g()
print("After g: ", a, b)

# Okay, now what if we look at lists, not just ints?
def h(vals):
    if len(vals) > 0:
        vals[0] = "apple"
    print("In h:    ", vals)

print("\n### TEST 4 ###")
lst = ['a', 'b', 'c', 'd']
print("Before h:", lst)
h(lst)
print("After h: ", lst)