from __future__ import nested_scopes
from test.test_support import verify,TestFailed,check_syntax
print "1. simple nesting"
def make_adder(x):
def adder(y):
return x + y
return adder
inc = make_adder(1)
plus10 = make_adder(10)
verify(inc(1) == 2)
verify(plus10(-2) == 8)
print "2. extra nesting"
def make_adder2(x):
def extra(): # check freevars passing through non-use scopes
def adder(y):
return x + y
return adder
return extra()
inc = make_adder2(1)
plus10 = make_adder2(10)
verify(inc(1) == 2)
verify(plus10(-2) == 8)
print "3. simple nesting + rebinding"
def make_adder3(x):
def adder(y):
return x + y
x = x + 1 # check tracking of assignment to x in defining scope
return adder
inc = make_adder3(0)
plus10 = make_adder3(9)
verify(inc(1) == 2)
verify(plus10(-2) == 8)
print "4. nesting with global but no free"
def make_adder4(): # XXX add exta level of indirection
def nest():
def nest():
def adder(y):
return global_x + y # check that plain old globals work
return adder
return nest()
return nest()
global_x = 1
adder = make_adder4()
verify(adder(1) == 2)
global_x = 10
verify(adder(-2) == 8)
print "5. nesting through class"
def make_adder5(x):
class Adder:
def __call__(self, y):
return x + y
return Adder()
inc = make_adder5(1)
plus10 = make_adder5(10)
verify(inc(1) == 2)
verify(plus10(-2) == 8)
print "6. nesting plus free ref to global"
def make_adder6(x):
global global_nest_x
def adder(y):
return global_nest_x + y
global_nest_x = x
return adder
inc = make_adder6(1)
plus10 = make_adder6(10)
verify(inc(1) == 11) # there's only one global
verify(plus10(-2) == 8)
print "7. nearest enclosing scope"
def f(x):
def g(y):
x = 42 # check that this masks binding in f()
def h(z):
return x + z
return h
return g(2)
test_func = f(10)
verify(test_func(5) == 47)
print "8. mixed freevars and cellvars"
def identity(x):
return x
def f(x, y, z):
def g(a, b, c):
a = a + x # 3
def h():
# z * (4 + 9)
# 3 * 13
return identity(z * (b + y))
y = c + z # 9
return h
return g
g = f(1, 2, 3)
h = g(2, 4, 6)
verify(h() == 39)
print "9. free variable in method"
def test():
method_and_var = "var"
class Test:
def method_and_var(self):
return "method"
def test(self):
return method_and_var
def actual_global(self):
return str("global")
def str(self):
return str(self)
return Test()
t = test()
verify(t.test() == "var")
verify(t.method_and_var() == "method")
verify(t.actual_global() == "global")
method_and_var = "var"
class Test:
# this class is not nested, so the rules are different
def method_and_var(self):
return "method"
def test(self):
return method_and_var
def actual_global(self):
return str("global")
def str(self):
return str(self)
t = Test()
verify(t.test() == "var")
verify(t.method_and_var() == "method")
verify(t.actual_global() == "global")
print "10. recursion"
def f(x):
def fact(n):
if n == 0:
return 1
else:
return n * fact(n - 1)
if x >= 0:
return fact(x)
else:
raise ValueError, "x must be >= 0"
verify(f(6) == 720)
print "11. unoptimized namespaces"
check_syntax("""from __future__ import nested_scopes
def unoptimized_clash1(strip):
def f(s):
from string import *
return strip(s) # ambiguity: free or local
return f
""")
check_syntax("""from __future__ import nested_scopes
def unoptimized_clash2():
from string import *
def f(s):
return strip(s) # ambiguity: global or local
return f
""")
check_syntax("""from __future__ import nested_scopes
def unoptimized_clash2():
from string import *
def g():
def f(s):
return strip(s) # ambiguity: global or local
return f
""")
# XXX could allow this for exec with const argument, but what's the point
check_syntax("""from __future__ import nested_scopes
def error(y):
exec "a = 1"
def f(x):
return x + y
return f
""")
check_syntax("""from __future__ import nested_scopes
def f(x):
def g():
return x
del x # can't del name
""")
check_syntax("""from __future__ import nested_scopes
def f():
def g():
from string import *
return strip # global or local?
""")
# and verify a few cases that should work
def noproblem1():
from string import *
f = lambda x:x
def noproblem2():
from string import *
def f(x):
return x + 1
def noproblem3():
from string import *
def f(x):
global y
y = x
print "12. lambdas"
f1 = lambda x: lambda y: x + y
inc = f1(1)
plus10 = f1(10)
verify(inc(1) == 2)
verify(plus10(5) == 15)
f2 = lambda x: (lambda : lambda y: x + y)()
inc = f2(1)
plus10 = f2(10)
verify(inc(1) == 2)
verify(plus10(5) == 15)
f3 = lambda x: lambda y: global_x + y
global_x = 1
inc = f3(None)
verify(inc(2) == 3)
f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y)
g = f8(1, 2, 3)
h = g(2, 4, 6)
verify(h() == 18)
print "13. UnboundLocal"
def errorInOuter():
print y
def inner():
return y
y = 1
def errorInInner():
def inner():
return y
inner()
y = 1
try:
errorInOuter()
except UnboundLocalError:
pass
else:
raise TestFailed
try:
errorInInner()
except NameError:
pass
else:
raise TestFailed
print "14. complex definitions"
def makeReturner(*lst):
def returner():
return lst
return returner
verify(makeReturner(1,2,3)() == (1,2,3))
def makeReturner2(**kwargs):
def returner():
return kwargs
return returner
verify(makeReturner2(a=11)()['a'] == 11)
def makeAddPair((a, b)):
def addPair((c, d)):
return (a + c, b + d)
return addPair
verify(makeAddPair((1, 2))((100, 200)) == (101,202))
print "15. scope of global statements"
# Examples posted by Samuele Pedroni to python-dev on 3/1/2001
# I
x = 7
def f():
x = 1
def g():
global x
def i():
def h():
return x
return h()
return i()
return g()
verify(f() == 7)
verify(x == 7)
# II
x = 7
def f():
x = 1
def g():
x = 2
def i():
def h():
return x
return h()
return i()
return g()
verify(f() == 2)
verify(x == 7)
# III
x = 7
def f():
x = 1
def g():
global x
x = 2
def i():
def h():
return x
return h()
return i()
return g()
verify(f() == 2)
verify(x == 2)
# IV
x = 7
def f():
x = 3
def g():
global x
x = 2
def i():
def h():
return x
return h()
return i()
return g()
verify(f() == 2)
verify(x == 2)
print "16. check leaks"
class Foo:
count = 0
def __init__(self):
Foo.count += 1
def __del__(self):
Foo.count -= 1
def f1():
x = Foo()
def f2():
return x
f2()
for i in range(100):
f1()
verify(Foo.count == 0)
print "17. class and global"
def test(x):
class Foo:
global x
def __call__(self, y):
return x + y
return Foo()
x = 0
verify(test(6)(2) == 8)
x = -1
verify(test(3)(2) == 5)
print "18. verify that locals() works"
def f(x):
def g(y):
def h(z):
return y + z
w = x + y
y += 3
return locals()
return g
d = f(2)(4)
verify(d.has_key('h'))
del d['h']
verify(d == {'x': 2, 'y': 7, 'w': 6})
print "19. var is bound and free in class"
def f(x):
class C:
def m(self):
return x
a = x
return C
inst = f(3)()
verify(inst.a == inst.m())
print "20. interaction with trace function"
import sys
def tracer(a,b,c):
return tracer
def adaptgetter(name, klass, getter):
kind, des = getter
if kind == 1: # AV happens when stepping from this line to next
if des == "":
des = "_%s__%s" % (klass.__name__, name)
return lambda obj: getattr(obj, des)
class TestClass:
pass
sys.settrace(tracer)
adaptgetter("foo", TestClass, (1, ""))
sys.settrace(None)
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