# scope.py

x = 1

def f():
    print "x inside f():", x

f()

def f():
    x = 'foo'
    print "x inside f():", x

f()
print "global x:", x

def f():
    global x
    x = 'foo'

f()
print "global x:", x

# Note how y doesn't exist in m until now
import m
m.y = 'xyz'
m.g()

# clean up for later section
del x

print


# Shadowing

def f():
    print "Builtin str():", str(123)
f()

str = "abc"
def f():
    print "Global str:", str
f()

def f():
    str = 456
    print "Local str:", str
f()

print "Global str:", str

del str
print "Builtin str():", str(123)

print


# This nested scope works
def f():
    x = 1
    def g():
        print "x inside g():", x
    g()

f()

# This "nested scope" doesn't work
def f():
    x = 1
    g()

def g():
    try:
        # Notice half this print executes before exception
        print "x inside g():", x
    except NameError:
        print "Sorry, can't access f()'s x"

f()


# Nested funcs can be closures

def f(x):
    def g(y):
        print "x,y inside g():", x, y
    return g

func = f(3)
func('abc')


# Cross-module scopes
# Although h is local scope, it picks up m.y (not y) because
# h's code object is still m.g

h = m.g
m.y = 4
y = 'foo'
h()


print


# Now for some classes

x = 'abc'

class Foo:
    pass

class Bar(Foo):
    pass

class Baz(Bar):
    def f(self):
        self.x = 'xyz'

    def g(self):
        return x

a = Baz()
Foo.x = 5
print "a.x gets Foo.x:", a.x
Bar.x = 'pdq'
print "a.x gets Bar.x:", a.x
a.f()
print "a.x gets a.x:", a.x
print "Foo().x gets Foo.x:", Foo().x
print "global x is", a.g()