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v0.8.1
v0.8.1
https://github.com/python/cpython
Tip revision: 1da43e5e916949c8e849e656d9d05fa4b9d6836c authored by Benjamin Peterson on 26 June 2009, 13:21:52 UTC
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
Tip revision: 1da43e5
test_scope.py
import unittest
from test.support import check_syntax_error, run_unittest
import warnings
warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<test string>")
warnings.filterwarnings("ignore", r"import \*", SyntaxWarning, "<string>")
class ScopeTests(unittest.TestCase):
def testSimpleNesting(self):
def make_adder(x):
def adder(y):
return x + y
return adder
inc = make_adder(1)
plus10 = make_adder(10)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(-2), 8)
def testExtraNesting(self):
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)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(-2), 8)
def testSimpleAndRebinding(self):
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)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(-2), 8)
def testNestingGlobalNoFree(self):
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()
self.assertEqual(adder(1), 2)
global_x = 10
self.assertEqual(adder(-2), 8)
def testNestingThroughClass(self):
def make_adder5(x):
class Adder:
def __call__(self, y):
return x + y
return Adder()
inc = make_adder5(1)
plus10 = make_adder5(10)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(-2), 8)
def testNestingPlusFreeRefToGlobal(self):
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)
self.assertEqual(inc(1), 11) # there's only one global
self.assertEqual(plus10(-2), 8)
def testNearestEnclosingScope(self):
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)
self.assertEqual(test_func(5), 47)
def testMixedFreevarsAndCellvars(self):
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)
self.assertEqual(h(), 39)
def testFreeVarInMethod(self):
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()
self.assertEqual(t.test(), "var")
self.assertEqual(t.method_and_var(), "method")
self.assertEqual(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()
self.assertEqual(t.test(), "var")
self.assertEqual(t.method_and_var(), "method")
self.assertEqual(t.actual_global(), "global")
def testCellIsKwonlyArg(self):
# Issue 1409: Initialisation of a cell value,
# when it comes from a keyword-only parameter
def foo(*, a=17):
def bar():
return a + 5
return bar() + 3
self.assertEqual(foo(a=42), 50)
self.assertEqual(foo(), 25)
def testRecursion(self):
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")
self.assertEqual(f(6), 720)
def testUnoptimizedNamespaces(self):
check_syntax_error(self, """\
def unoptimized_clash1(strip):
def f(s):
from sys import *
return getrefcount(s) # ambiguity: free or local
return f
""")
check_syntax_error(self, """\
def unoptimized_clash2():
from sys import *
def f(s):
return getrefcount(s) # ambiguity: global or local
return f
""")
check_syntax_error(self, """\
def unoptimized_clash2():
from sys import *
def g():
def f(s):
return getrefcount(s) # ambiguity: global or local
return f
""")
check_syntax_error(self, """\
def f(x):
def g():
return x
del x # can't del name
""")
check_syntax_error(self, """\
def f():
def g():
from sys import *
return getrefcount # global or local?
""")
def testLambdas(self):
f1 = lambda x: lambda y: x + y
inc = f1(1)
plus10 = f1(10)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(5), 15)
f2 = lambda x: (lambda : lambda y: x + y)()
inc = f2(1)
plus10 = f2(10)
self.assertEqual(inc(1), 2)
self.assertEqual(plus10(5), 15)
f3 = lambda x: lambda y: global_x + y
global_x = 1
inc = f3(None)
self.assertEqual(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)
self.assertEqual(h(), 18)
def testUnboundLocal(self):
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:
self.fail()
try:
errorInInner()
except NameError:
pass
else:
self.fail()
# test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation
exec("""
global_x = 1
def f():
global_x += 1
try:
f()
except UnboundLocalError:
pass
else:
fail('scope of global_x not correctly determined')
""", {'fail': self.fail})
def testComplexDefinitions(self):
def makeReturner(*lst):
def returner():
return lst
return returner
self.assertEqual(makeReturner(1,2,3)(), (1,2,3))
def makeReturner2(**kwargs):
def returner():
return kwargs
return returner
self.assertEqual(makeReturner2(a=11)()['a'], 11)
def testScopeOfGlobalStmt(self):
# Examples posted by Samuele Pedroni to python-dev on 3/1/2001
exec("""\
# I
x = 7
def f():
x = 1
def g():
global x
def i():
def h():
return x
return h()
return i()
return g()
self.assertEqual(f(), 7)
self.assertEqual(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()
self.assertEqual(f(), 2)
self.assertEqual(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()
self.assertEqual(f(), 2)
self.assertEqual(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()
self.assertEqual(f(), 2)
self.assertEqual(x, 2)
# XXX what about global statements in class blocks?
# do they affect methods?
x = 12
class Global:
global x
x = 13
def set(self, val):
x = val
def get(self):
return x
g = Global()
self.assertEqual(g.get(), 13)
g.set(15)
self.assertEqual(g.get(), 13)
""")
def testLeaks(self):
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()
self.assertEqual(Foo.count, 0)
def testClassAndGlobal(self):
exec("""\
def test(x):
class Foo:
global x
def __call__(self, y):
return x + y
return Foo()
x = 0
self.assertEqual(test(6)(2), 8)
x = -1
self.assertEqual(test(3)(2), 5)
looked_up_by_load_name = False
class X:
# Implicit globals inside classes are be looked up by LOAD_NAME, not
# LOAD_GLOBAL.
locals()['looked_up_by_load_name'] = True
passed = looked_up_by_load_name
self.assert_(X.passed)
""")
def testLocalsFunction(self):
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)
self.assert_('h' in d)
del d['h']
self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6})
def testLocalsClass(self):
# This test verifies that calling locals() does not pollute
# the local namespace of the class with free variables. Old
# versions of Python had a bug, where a free variable being
# passed through a class namespace would be inserted into
# locals() by locals() or exec or a trace function.
#
# The real bug lies in frame code that copies variables
# between fast locals and the locals dict, e.g. when executing
# a trace function.
def f(x):
class C:
x = 12
def m(self):
return x
locals()
return C
self.assertEqual(f(1).x, 12)
def f(x):
class C:
y = x
def m(self):
return x
z = list(locals())
return C
varnames = f(1).z
self.assert_("x" not in varnames)
self.assert_("y" in varnames)
def testLocalsClass_WithTrace(self):
# Issue23728: after the trace function returns, the locals()
# dictionary is used to update all variables, this used to
# include free variables. But in class statements, free
# variables are not inserted...
import sys
sys.settrace(lambda a,b,c:None)
try:
x = 12
class C:
def f(self):
return x
self.assertEquals(x, 12) # Used to raise UnboundLocalError
finally:
sys.settrace(None)
def testBoundAndFree(self):
# var is bound and free in class
def f(x):
class C:
def m(self):
return x
a = x
return C
inst = f(3)()
self.assertEqual(inst.a, inst.m())
def testInteractionWithTraceFunc(self):
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)
self.assertRaises(TypeError, sys.settrace)
def testEvalExecFreeVars(self):
def f(x):
return lambda: x + 1
g = f(3)
self.assertRaises(TypeError, eval, g.__code__)
try:
exec(g.__code__, {})
except TypeError:
pass
else:
self.fail("exec should have failed, because code contained free vars")
def testListCompLocalVars(self):
try:
print(bad)
except NameError:
pass
else:
print("bad should not be defined")
def x():
[bad for s in 'a b' for bad in s.split()]
x()
try:
print(bad)
except NameError:
pass
def testEvalFreeVars(self):
def f(x):
def g():
x
eval("x + 1")
return g
f(4)()
def testFreeingCell(self):
# Test what happens when a finalizer accesses
# the cell where the object was stored.
class Special:
def __del__(self):
nestedcell_get()
def testNonLocalFunction(self):
def f(x):
def inc():
nonlocal x
x += 1
return x
def dec():
nonlocal x
x -= 1
return x
return inc, dec
inc, dec = f(0)
self.assertEqual(inc(), 1)
self.assertEqual(inc(), 2)
self.assertEqual(dec(), 1)
self.assertEqual(dec(), 0)
def testNonLocalMethod(self):
def f(x):
class c:
def inc(self):
nonlocal x
x += 1
return x
def dec(self):
nonlocal x
x -= 1
return x
return c()
c = f(0)
self.assertEqual(c.inc(), 1)
self.assertEqual(c.inc(), 2)
self.assertEqual(c.dec(), 1)
self.assertEqual(c.dec(), 0)
def testGlobalInParallelNestedFunctions(self):
# A symbol table bug leaked the global statement from one
# function to other nested functions in the same block.
# This test verifies that a global statement in the first
# function does not affect the second function.
CODE = """def f():
y = 1
def g():
global y
return y
def h():
return y + 1
return g, h
y = 9
g, h = f()
result9 = g()
result2 = h()
"""
local_ns = {}
global_ns = {}
exec(CODE, local_ns, global_ns)
self.assertEqual(2, global_ns["result2"])
self.assertEqual(9, global_ns["result9"])
def testNonLocalClass(self):
def f(x):
class c:
nonlocal x
x += 1
def get(self):
return x
return c()
c = f(0)
self.assertEqual(c.get(), 1)
self.assert_("x" not in c.__class__.__dict__)
def testNonLocalGenerator(self):
def f(x):
def g(y):
nonlocal x
for i in range(y):
x += 1
yield x
return g
g = f(0)
self.assertEqual(list(g(5)), [1, 2, 3, 4, 5])
def testNestedNonLocal(self):
def f(x):
def g():
nonlocal x
x -= 2
def h():
nonlocal x
x += 4
return x
return h
return g
g = f(1)
h = g()
self.assertEqual(h(), 3)
def test_main():
run_unittest(ScopeTests)
if __name__ == '__main__':
test_main()