| import unittest |
| import weakref |
| |
| from test.support import check_syntax_error, cpython_only |
| |
| |
| 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, """if 1: |
| def unoptimized_clash1(strip): |
| def f(s): |
| from sys import * |
| return getrefcount(s) # ambiguity: free or local |
| return f |
| """) |
| |
| check_syntax_error(self, """if 1: |
| def unoptimized_clash2(): |
| from sys import * |
| def f(s): |
| return getrefcount(s) # ambiguity: global or local |
| return f |
| """) |
| |
| check_syntax_error(self, """if 1: |
| def unoptimized_clash2(): |
| from sys import * |
| def g(): |
| def f(s): |
| return getrefcount(s) # ambiguity: global or local |
| return f |
| """) |
| |
| check_syntax_error(self, """if 1: |
| 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 |
| |
| self.assertRaises(UnboundLocalError, errorInOuter) |
| self.assertRaises(NameError, errorInInner) |
| |
| def testUnboundLocal_AfterDel(self): |
| # #4617: It is now legal to delete a cell variable. |
| # The following functions must obviously compile, |
| # and give the correct error when accessing the deleted name. |
| def errorInOuter(): |
| y = 1 |
| del y |
| print(y) |
| def inner(): |
| return y |
| |
| def errorInInner(): |
| def inner(): |
| return y |
| y = 1 |
| del y |
| inner() |
| |
| self.assertRaises(UnboundLocalError, errorInOuter) |
| self.assertRaises(NameError, errorInInner) |
| |
| def testUnboundLocal_AugAssign(self): |
| # test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation |
| exec("""if 1: |
| 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("""if 1: |
| # 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("""if 1: |
| 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.assertTrue(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.assertIn('h', 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.assertNotIn("x", varnames) |
| self.assertIn("y", varnames) |
| |
| @cpython_only |
| 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 |
| self.addCleanup(sys.settrace, sys.gettrace()) |
| sys.settrace(lambda a,b,c:None) |
| x = 12 |
| |
| class C: |
| def f(self): |
| return x |
| |
| self.assertEqual(x, 12) # Used to raise UnboundLocalError |
| |
| 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()) |
| |
| @cpython_only |
| 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 |
| |
| self.addCleanup(sys.settrace, sys.gettrace()) |
| 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. |
| local_ns = {} |
| global_ns = {} |
| exec("""if 1: |
| 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) |
| 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.assertNotIn("x", 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 testTopIsNotSignificant(self): |
| # See #9997. |
| def top(a): |
| pass |
| def b(): |
| global a |
| |
| def testClassNamespaceOverridesClosure(self): |
| # See #17853. |
| x = 42 |
| class X: |
| locals()["x"] = 43 |
| y = x |
| self.assertEqual(X.y, 43) |
| class X: |
| locals()["x"] = 43 |
| del x |
| self.assertFalse(hasattr(X, "x")) |
| self.assertEqual(x, 42) |
| |
| @cpython_only |
| def testCellLeak(self): |
| # Issue 17927. |
| # |
| # The issue was that if self was part of a cycle involving the |
| # frame of a method call, *and* the method contained a nested |
| # function referencing self, thereby forcing 'self' into a |
| # cell, setting self to None would not be enough to break the |
| # frame -- the frame had another reference to the instance, |
| # which could not be cleared by the code running in the frame |
| # (though it will be cleared when the frame is collected). |
| # Without the lambda, setting self to None is enough to break |
| # the cycle. |
| class Tester: |
| def dig(self): |
| if 0: |
| lambda: self |
| try: |
| 1/0 |
| except Exception as exc: |
| self.exc = exc |
| self = None # Break the cycle |
| tester = Tester() |
| tester.dig() |
| ref = weakref.ref(tester) |
| del tester |
| self.assertIsNone(ref()) |
| |
| |
| if __name__ == '__main__': |
| unittest.main() |