mirror of https://github.com/python/cpython
813 lines
21 KiB
Python
813 lines
21 KiB
Python
import unittest
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import weakref
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from test.support import check_syntax_error, cpython_only
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class ScopeTests(unittest.TestCase):
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def testSimpleNesting(self):
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def make_adder(x):
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def adder(y):
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return x + y
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return adder
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inc = make_adder(1)
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plus10 = make_adder(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testExtraNesting(self):
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def make_adder2(x):
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def extra(): # check freevars passing through non-use scopes
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def adder(y):
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return x + y
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return adder
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return extra()
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inc = make_adder2(1)
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plus10 = make_adder2(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testSimpleAndRebinding(self):
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def make_adder3(x):
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def adder(y):
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return x + y
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x = x + 1 # check tracking of assignment to x in defining scope
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return adder
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inc = make_adder3(0)
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plus10 = make_adder3(9)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testNestingGlobalNoFree(self):
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def make_adder4(): # XXX add exta level of indirection
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def nest():
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def nest():
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def adder(y):
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return global_x + y # check that plain old globals work
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return adder
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return nest()
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return nest()
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global_x = 1
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adder = make_adder4()
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self.assertEqual(adder(1), 2)
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global_x = 10
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self.assertEqual(adder(-2), 8)
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def testNestingThroughClass(self):
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def make_adder5(x):
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class Adder:
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def __call__(self, y):
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return x + y
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return Adder()
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inc = make_adder5(1)
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plus10 = make_adder5(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(-2), 8)
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def testNestingPlusFreeRefToGlobal(self):
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def make_adder6(x):
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global global_nest_x
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def adder(y):
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return global_nest_x + y
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global_nest_x = x
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return adder
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inc = make_adder6(1)
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plus10 = make_adder6(10)
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self.assertEqual(inc(1), 11) # there's only one global
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self.assertEqual(plus10(-2), 8)
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def testNearestEnclosingScope(self):
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def f(x):
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def g(y):
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x = 42 # check that this masks binding in f()
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def h(z):
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return x + z
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return h
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return g(2)
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test_func = f(10)
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self.assertEqual(test_func(5), 47)
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def testMixedFreevarsAndCellvars(self):
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def identity(x):
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return x
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def f(x, y, z):
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def g(a, b, c):
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a = a + x # 3
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def h():
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# z * (4 + 9)
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# 3 * 13
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return identity(z * (b + y))
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y = c + z # 9
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return h
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return g
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g = f(1, 2, 3)
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h = g(2, 4, 6)
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self.assertEqual(h(), 39)
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def testFreeVarInMethod(self):
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def test():
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method_and_var = "var"
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class Test:
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def method_and_var(self):
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return "method"
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def test(self):
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return method_and_var
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def actual_global(self):
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return str("global")
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def str(self):
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return str(self)
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return Test()
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t = test()
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self.assertEqual(t.test(), "var")
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self.assertEqual(t.method_and_var(), "method")
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self.assertEqual(t.actual_global(), "global")
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method_and_var = "var"
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class Test:
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# this class is not nested, so the rules are different
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def method_and_var(self):
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return "method"
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def test(self):
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return method_and_var
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def actual_global(self):
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return str("global")
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def str(self):
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return str(self)
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t = Test()
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self.assertEqual(t.test(), "var")
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self.assertEqual(t.method_and_var(), "method")
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self.assertEqual(t.actual_global(), "global")
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def testCellIsKwonlyArg(self):
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# Issue 1409: Initialisation of a cell value,
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# when it comes from a keyword-only parameter
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def foo(*, a=17):
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def bar():
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return a + 5
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return bar() + 3
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self.assertEqual(foo(a=42), 50)
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self.assertEqual(foo(), 25)
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def testCellIsArgAndEscapes(self):
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# We need to be sure that a cell passed in as an arg still
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# gets wrapped in a new cell if the arg escapes into an
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# inner function (closure).
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def external():
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value = 42
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def inner():
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return value
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cell, = inner.__closure__
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return cell
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cell_ext = external()
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def spam(arg):
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def eggs():
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return arg
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return eggs
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eggs = spam(cell_ext)
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cell_closure, = eggs.__closure__
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cell_eggs = eggs()
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self.assertIs(cell_eggs, cell_ext)
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self.assertIsNot(cell_eggs, cell_closure)
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def testCellIsLocalAndEscapes(self):
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# We need to be sure that a cell bound to a local still
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# gets wrapped in a new cell if the local escapes into an
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# inner function (closure).
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def external():
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value = 42
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def inner():
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return value
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cell, = inner.__closure__
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return cell
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cell_ext = external()
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def spam(arg):
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cell = arg
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def eggs():
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return cell
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return eggs
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eggs = spam(cell_ext)
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cell_closure, = eggs.__closure__
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cell_eggs = eggs()
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self.assertIs(cell_eggs, cell_ext)
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self.assertIsNot(cell_eggs, cell_closure)
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def testRecursion(self):
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def f(x):
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def fact(n):
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if n == 0:
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return 1
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else:
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return n * fact(n - 1)
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if x >= 0:
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return fact(x)
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else:
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raise ValueError("x must be >= 0")
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self.assertEqual(f(6), 720)
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def testUnoptimizedNamespaces(self):
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check_syntax_error(self, """if 1:
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def unoptimized_clash1(strip):
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def f(s):
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from sys import *
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return getrefcount(s) # ambiguity: free or local
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return f
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""")
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check_syntax_error(self, """if 1:
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def unoptimized_clash2():
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from sys import *
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def f(s):
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return getrefcount(s) # ambiguity: global or local
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return f
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""")
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check_syntax_error(self, """if 1:
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def unoptimized_clash2():
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from sys import *
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def g():
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def f(s):
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return getrefcount(s) # ambiguity: global or local
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return f
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""")
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check_syntax_error(self, """if 1:
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def f():
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def g():
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from sys import *
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return getrefcount # global or local?
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""")
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def testLambdas(self):
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f1 = lambda x: lambda y: x + y
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inc = f1(1)
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plus10 = f1(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(5), 15)
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f2 = lambda x: (lambda : lambda y: x + y)()
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inc = f2(1)
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plus10 = f2(10)
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self.assertEqual(inc(1), 2)
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self.assertEqual(plus10(5), 15)
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f3 = lambda x: lambda y: global_x + y
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global_x = 1
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inc = f3(None)
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self.assertEqual(inc(2), 3)
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f8 = lambda x, y, z: lambda a, b, c: lambda : z * (b + y)
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g = f8(1, 2, 3)
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h = g(2, 4, 6)
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self.assertEqual(h(), 18)
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def testUnboundLocal(self):
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def errorInOuter():
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print(y)
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def inner():
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return y
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y = 1
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def errorInInner():
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def inner():
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return y
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inner()
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y = 1
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self.assertRaises(UnboundLocalError, errorInOuter)
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self.assertRaises(NameError, errorInInner)
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def testUnboundLocal_AfterDel(self):
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# #4617: It is now legal to delete a cell variable.
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# The following functions must obviously compile,
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# and give the correct error when accessing the deleted name.
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def errorInOuter():
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y = 1
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del y
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print(y)
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def inner():
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return y
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def errorInInner():
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def inner():
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return y
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y = 1
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del y
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inner()
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self.assertRaises(UnboundLocalError, errorInOuter)
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self.assertRaises(NameError, errorInInner)
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def testUnboundLocal_AugAssign(self):
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# test for bug #1501934: incorrect LOAD/STORE_GLOBAL generation
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exec("""if 1:
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global_x = 1
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def f():
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global_x += 1
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try:
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f()
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except UnboundLocalError:
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pass
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else:
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fail('scope of global_x not correctly determined')
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""", {'fail': self.fail})
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def testComplexDefinitions(self):
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def makeReturner(*lst):
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def returner():
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return lst
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return returner
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self.assertEqual(makeReturner(1,2,3)(), (1,2,3))
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def makeReturner2(**kwargs):
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def returner():
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return kwargs
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return returner
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self.assertEqual(makeReturner2(a=11)()['a'], 11)
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def testScopeOfGlobalStmt(self):
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# Examples posted by Samuele Pedroni to python-dev on 3/1/2001
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exec("""if 1:
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# I
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x = 7
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def f():
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x = 1
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def g():
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global x
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 7)
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self.assertEqual(x, 7)
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# II
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x = 7
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def f():
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x = 1
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def g():
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 7)
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# III
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x = 7
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def f():
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x = 1
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def g():
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global x
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 2)
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# IV
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x = 7
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def f():
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x = 3
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def g():
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global x
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x = 2
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def i():
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def h():
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return x
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return h()
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return i()
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return g()
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self.assertEqual(f(), 2)
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self.assertEqual(x, 2)
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# XXX what about global statements in class blocks?
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# do they affect methods?
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x = 12
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class Global:
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global x
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x = 13
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def set(self, val):
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x = val
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def get(self):
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return x
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g = Global()
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self.assertEqual(g.get(), 13)
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g.set(15)
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self.assertEqual(g.get(), 13)
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""")
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def testLeaks(self):
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class Foo:
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count = 0
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def __init__(self):
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Foo.count += 1
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def __del__(self):
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Foo.count -= 1
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def f1():
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x = Foo()
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def f2():
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return x
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f2()
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for i in range(100):
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f1()
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self.assertEqual(Foo.count, 0)
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def testClassAndGlobal(self):
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exec("""if 1:
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def test(x):
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class Foo:
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global x
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def __call__(self, y):
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return x + y
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return Foo()
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x = 0
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self.assertEqual(test(6)(2), 8)
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x = -1
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self.assertEqual(test(3)(2), 5)
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looked_up_by_load_name = False
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class X:
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# Implicit globals inside classes are be looked up by LOAD_NAME, not
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# LOAD_GLOBAL.
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locals()['looked_up_by_load_name'] = True
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passed = looked_up_by_load_name
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self.assertTrue(X.passed)
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""")
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def testLocalsFunction(self):
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def f(x):
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def g(y):
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def h(z):
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return y + z
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w = x + y
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y += 3
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return locals()
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return g
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d = f(2)(4)
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self.assertIn('h', d)
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del d['h']
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self.assertEqual(d, {'x': 2, 'y': 7, 'w': 6})
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def testLocalsClass(self):
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# This test verifies that calling locals() does not pollute
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# the local namespace of the class with free variables. Old
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# versions of Python had a bug, where a free variable being
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# passed through a class namespace would be inserted into
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# locals() by locals() or exec or a trace function.
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#
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# The real bug lies in frame code that copies variables
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# between fast locals and the locals dict, e.g. when executing
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# a trace function.
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def f(x):
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class C:
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x = 12
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def m(self):
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return x
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locals()
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return C
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self.assertEqual(f(1).x, 12)
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def f(x):
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class C:
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y = x
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def m(self):
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return x
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z = list(locals())
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return C
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varnames = f(1).z
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self.assertNotIn("x", varnames)
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self.assertIn("y", varnames)
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@cpython_only
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def testLocalsClass_WithTrace(self):
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# Issue23728: after the trace function returns, the locals()
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# dictionary is used to update all variables, this used to
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# include free variables. But in class statements, free
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# variables are not inserted...
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import sys
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self.addCleanup(sys.settrace, sys.gettrace())
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sys.settrace(lambda a,b,c:None)
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x = 12
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class C:
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def f(self):
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return x
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self.assertEqual(x, 12) # Used to raise UnboundLocalError
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def testBoundAndFree(self):
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# var is bound and free in class
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def f(x):
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class C:
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def m(self):
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return x
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a = x
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return C
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inst = f(3)()
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self.assertEqual(inst.a, inst.m())
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@cpython_only
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def testInteractionWithTraceFunc(self):
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import sys
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def tracer(a,b,c):
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return tracer
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def adaptgetter(name, klass, getter):
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kind, des = getter
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if kind == 1: # AV happens when stepping from this line to next
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if des == "":
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des = "_%s__%s" % (klass.__name__, name)
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return lambda obj: getattr(obj, des)
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class TestClass:
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pass
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self.addCleanup(sys.settrace, sys.gettrace())
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sys.settrace(tracer)
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adaptgetter("foo", TestClass, (1, ""))
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sys.settrace(None)
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self.assertRaises(TypeError, sys.settrace)
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def testEvalExecFreeVars(self):
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def f(x):
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return lambda: x + 1
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g = f(3)
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self.assertRaises(TypeError, eval, g.__code__)
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try:
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exec(g.__code__, {})
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except TypeError:
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pass
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else:
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self.fail("exec should have failed, because code contained free vars")
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def testListCompLocalVars(self):
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try:
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print(bad)
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except NameError:
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pass
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else:
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print("bad should not be defined")
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def x():
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[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()
|