python try/catch/finally

python_try_catch_finally_order_of_evaluation.py

def f(): # returns "bar"
    try:
        a = "foo"
        return a
    finally:
        a = "bar"
        return a
# order of evaluation:
# 3:a = "foo"
# 4:return a -eval-> return "foo"
# 6:a = "bar"
# 7:return a -eval-> return "bar"
# 7:return "bar"

def g(): # returns "foo"
    try:
        a = "foo"
        return a
    finally:
        a = "bar"
# order of evaluation:
# 17:a = "foo"
# 18:return a -eval-> return "foo"
# 19:a = "bar"
# 18: return "foo"

def h(a): # returns ["bar"]
    try:
        a[0] = "foo"
        return a
    finally:
        a[0] = "bar"

def k(a): # returns "foo"
    try:
        a[0] = "foo"
        return a[0]
    finally:
        a[0] = "bar"

# The finally block is invoked after the expression in the return statement is evaluated

print(f()) # "bar"
print(g()) # "foo"
print h(["spam"]) # ["bar"]
print k(["spam"]) # "foo"