# File: scope.py
# Program to show how scope works with functions
#
# General rule: LEGB
# -- first, look for names assigned in any way in the local function (def)
#    and *not* declared global
# -- next, look for local names in enclosing function definitions going
#    from innermost to outermost
# -- third, look for names assigned at the top level of the module (globals)
# -- fourth, look for names pre-assigned in buit-in names modules (like
#    open, range, SyntaxError, etc.)
#
# Matt Bishop, ECS 36A, Winter 2019

#
# a global variable
#
globbie = 1234

#
# first, a function that defines a local variable "globbie"
# note there is no "global" line
#
def func1():
    globbie = 16
    return globbie

#
# now, a function that sets the value of the global variable "globbie"
# note the "global" line
#
def func2():
    global globbie
    globbie = 18
    return globbie

#
# now, a function that defines a parameter "globbie"
# note there is no "global" line
# note: without the parameter, this gives an error
#
def func3(globbie):
    globbie = globbie + 1
    return globbie

#
# now we're going to nest functions
# here, the outer one changes a local globbie
# and the inner one changes the global globbie
#
def func4():
    globbie = 10
    y = func2()
    return y

#
# again we're going to nest functions
# here, the inner one references the global globbie,
# not the one defined in the outer function
# 
def func5a():
    y = globbie + 22
    return y
    
def func5():
    globbie = 10
    z = func5a()
    return z

#
# now we're going to nest function *definitions*
# here, the inner one references the globbie defined
# in the outer function, not the global one
# 
    
def func6():
    def func6a():
        y = globbie + 975
        return y
    globbie = 22
    z = func6a()
    return z

#
# pulling it all together
#
x = func1()
print("globbie =", globbie, "func1() returned =", x)
x = func2()
print("globbie =", globbie, "func2() returned =", x)
x = func3(5678)
print("globbie =", globbie, "func3() returned =", x)
globbie = 3456;
print("globbie =", globbie)
x = func4()
print("globbie =", globbie, "func4() returned =", x)
x = func5()
print("globbie =", globbie, "func5() returned =", x)
x = func6()
print("globbie =", globbie, "func6() returned =", x)