diff options
| -rw-r--r-- | Doc/reference/compound_stmts.rst | 20 | ||||
| -rw-r--r-- | Grammar/Grammar | 4 | ||||
| -rw-r--r-- | Include/graminit.h | 2 | ||||
| -rw-r--r-- | Lib/test/test_parser.py | 1 | ||||
| -rw-r--r-- | Lib/test/test_with.py | 78 | ||||
| -rw-r--r-- | Misc/NEWS | 2 | ||||
| -rw-r--r-- | Modules/parsermodule.c | 33 | ||||
| -rw-r--r-- | Python/ast.c | 61 | ||||
| -rw-r--r-- | Python/graminit.c | 39 |
9 files changed, 180 insertions, 60 deletions
diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst index 61e3067..214143b 100644 --- a/Doc/reference/compound_stmts.rst +++ b/Doc/reference/compound_stmts.rst @@ -347,9 +347,10 @@ This allows common :keyword:`try`...\ :keyword:`except`...\ :keyword:`finally` usage patterns to be encapsulated for convenient reuse. .. productionlist:: - with_stmt: "with" `expression` ["as" `target`] ":" `suite` + with_stmt: "with" with_item ("," with_item)* ":" `suite` + with_item: `expression` ["as" `target`] -The execution of the :keyword:`with` statement proceeds as follows: +The execution of the :keyword:`with` statement with one "item" proceeds as follows: #. The context expression is evaluated to obtain a context manager. @@ -382,6 +383,21 @@ The execution of the :keyword:`with` statement proceeds as follows: value from :meth:`__exit__` is ignored, and execution proceeds at the normal location for the kind of exit that was taken. +With more than one item, the context managers are processed as if multiple +:keyword:`with` statements were nested:: + + with A() as a, B() as b: + suite + +is equivalent to :: + + with A() as a: + with B() as b: + suite + +.. versionchanged:: 3.1 + Support for multiple context expressions. + .. seealso:: :pep:`0343` - The "with" statement diff --git a/Grammar/Grammar b/Grammar/Grammar index e9922c1..1b196e5 100644 --- a/Grammar/Grammar +++ b/Grammar/Grammar @@ -73,8 +73,8 @@ try_stmt: ('try' ':' suite ['else' ':' suite] ['finally' ':' suite] | 'finally' ':' suite)) -with_stmt: 'with' test [ with_var ] ':' suite -with_var: 'as' expr +with_stmt: 'with' with_item (',' with_item)* ':' suite +with_item: test ['as' expr] # NB compile.c makes sure that the default except clause is last except_clause: 'except' [test ['as' NAME]] suite: simple_stmt | NEWLINE INDENT stmt+ DEDENT diff --git a/Include/graminit.h b/Include/graminit.h index 5786d52..04f9b9a 100644 --- a/Include/graminit.h +++ b/Include/graminit.h @@ -42,7 +42,7 @@ #define for_stmt 295 #define try_stmt 296 #define with_stmt 297 -#define with_var 298 +#define with_item 298 #define except_clause 299 #define suite 300 #define test 301 diff --git a/Lib/test/test_parser.py b/Lib/test/test_parser.py index 86ede3e..65d1d35 100644 --- a/Lib/test/test_parser.py +++ b/Lib/test/test_parser.py @@ -193,6 +193,7 @@ class RoundtripLegalSyntaxTestCase(unittest.TestCase): def test_with(self): self.check_suite("with open('x'): pass\n") self.check_suite("with open('x') as f: pass\n") + self.check_suite("with open('x') as f, open('y') as g: pass\n") def test_try_stmt(self): self.check_suite("try: pass\nexcept: pass\n") diff --git a/Lib/test/test_with.py b/Lib/test/test_with.py index b192429..105be8b 100644 --- a/Lib/test/test_with.py +++ b/Lib/test/test_with.py @@ -656,12 +656,88 @@ class ExitSwallowsExceptionTestCase(unittest.TestCase): self.fail("ZeroDivisionError should have been raised") +class NestedWith(unittest.TestCase): + + class Dummy(object): + def __init__(self, value=None, gobble=False): + if value is None: + value = self + self.value = value + self.gobble = gobble + self.enter_called = False + self.exit_called = False + + def __enter__(self): + self.enter_called = True + return self.value + + def __exit__(self, *exc_info): + self.exit_called = True + self.exc_info = exc_info + if self.gobble: + return True + + class CtorRaises(object): + def __init__(self): raise RuntimeError() + + class EnterRaises(object): + def __enter__(self): raise RuntimeError() + def __exit__(self, *exc_info): pass + + class ExitRaises(object): + def __enter__(self): pass + def __exit__(self, *exc_info): raise RuntimeError() + + def testNoExceptions(self): + with self.Dummy() as a, self.Dummy() as b: + self.assertTrue(a.enter_called) + self.assertTrue(b.enter_called) + self.assertTrue(a.exit_called) + self.assertTrue(b.exit_called) + + def testExceptionInExprList(self): + try: + with self.Dummy() as a, self.CtorRaises(): + pass + except: + pass + self.assertTrue(a.enter_called) + self.assertTrue(a.exit_called) + + def testExceptionInEnter(self): + try: + with self.Dummy() as a, self.EnterRaises(): + self.fail('body of bad with executed') + except RuntimeError: + pass + else: + self.fail('RuntimeError not reraised') + self.assertTrue(a.enter_called) + self.assertTrue(a.exit_called) + + def testExceptionInExit(self): + body_executed = False + with self.Dummy(gobble=True) as a, self.ExitRaises(): + body_executed = True + self.assertTrue(a.enter_called) + self.assertTrue(a.exit_called) + self.assertNotEqual(a.exc_info[0], None) + + def testEnterReturnsTuple(self): + with self.Dummy(value=(1,2)) as (a1, a2), \ + self.Dummy(value=(10, 20)) as (b1, b2): + self.assertEquals(1, a1) + self.assertEquals(2, a2) + self.assertEquals(10, b1) + self.assertEquals(20, b2) + def test_main(): run_unittest(FailureTestCase, NonexceptionalTestCase, NestedNonexceptionalTestCase, ExceptionalTestCase, NonLocalFlowControlTestCase, AssignmentTargetTestCase, - ExitSwallowsExceptionTestCase) + ExitSwallowsExceptionTestCase, + NestedWith) if __name__ == '__main__': @@ -15,6 +15,8 @@ Core and Builtins - Issue #6089: Fixed str.format with certain invalid field specifiers that would raise SystemError. +- Added support for multiple context managers in the same with statement. + - Issue #5829: complex("1e500") no longer raises OverflowError. This makes it consistent with float("1e500") and interpretation of real and imaginary literals. diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c index 49f6e23..a16e69c 100644 --- a/Modules/parsermodule.c +++ b/Modules/parsermodule.c @@ -2446,36 +2446,39 @@ validate_decorators(node *tree) return ok; } -/* with_var -with_var: 'as' expr +/* with_item: + * test ['as' expr] */ static int -validate_with_var(node *tree) +validate_with_item(node *tree) { int nch = NCH(tree); - int ok = (validate_ntype(tree, with_var) - && (nch == 2) - && validate_name(CHILD(tree, 0), "as") - && validate_expr(CHILD(tree, 1))); - return ok; + int ok = (validate_ntype(tree, with_item) + && (nch == 1 || nch == 3) + && validate_test(CHILD(tree, 0))); + if (ok && nch == 3) + ok = (validate_name(CHILD(tree, 1), "as") + && validate_expr(CHILD(tree, 2))); + return ok; } -/* with_stmt - * 0 1 2 -2 -1 -with_stmt: 'with' test [ with_var ] ':' suite +/* with_stmt: + * 0 1 ... -2 -1 + * 'with' with_item (',' with_item)* ':' suite */ static int validate_with_stmt(node *tree) { + int i; int nch = NCH(tree); int ok = (validate_ntype(tree, with_stmt) - && ((nch == 4) || (nch == 5)) + && (nch % 2 == 0) && validate_name(CHILD(tree, 0), "with") - && validate_test(CHILD(tree, 1)) - && (nch == 4 || validate_with_var(CHILD(tree, 2))) && validate_colon(RCHILD(tree, -2)) && validate_suite(RCHILD(tree, -1))); - return ok; + for (i = 1; ok && i < nch - 2; i += 2) + ok = validate_with_item(CHILD(tree, i)); + return ok; } /* funcdef: diff --git a/Python/ast.c b/Python/ast.c index 1c79359..ff412b3 100644 --- a/Python/ast.c +++ b/Python/ast.c @@ -2959,25 +2959,16 @@ ast_for_try_stmt(struct compiling *c, const node *n) return TryFinally(body, finally, LINENO(n), n->n_col_offset, c->c_arena); } -static expr_ty -ast_for_with_var(struct compiling *c, const node *n) -{ - REQ(n, with_var); - return ast_for_expr(c, CHILD(n, 1)); -} - -/* with_stmt: 'with' test [ with_var ] ':' suite */ +/* with_item: test ['as' expr] */ static stmt_ty -ast_for_with_stmt(struct compiling *c, const node *n) +ast_for_with_item(struct compiling *c, const node *n, asdl_seq *content) { expr_ty context_expr, optional_vars = NULL; - int suite_index = 3; /* skip 'with', test, and ':' */ - asdl_seq *suite_seq; - assert(TYPE(n) == with_stmt); - context_expr = ast_for_expr(c, CHILD(n, 1)); - if (TYPE(CHILD(n, 2)) == with_var) { - optional_vars = ast_for_with_var(c, CHILD(n, 2)); + REQ(n, with_item); + context_expr = ast_for_expr(c, CHILD(n, 0)); + if (NCH(n) == 3) { + optional_vars = ast_for_expr(c, CHILD(n, 2)); if (!optional_vars) { return NULL; @@ -2985,15 +2976,45 @@ ast_for_with_stmt(struct compiling *c, const node *n) if (!set_context(c, optional_vars, Store, n)) { return NULL; } - suite_index = 4; } - suite_seq = ast_for_suite(c, CHILD(n, suite_index)); - if (!suite_seq) { + return With(context_expr, optional_vars, content, LINENO(n), + n->n_col_offset, c->c_arena); +} + +/* with_stmt: 'with' with_item (',' with_item)* ':' suite */ +static stmt_ty +ast_for_with_stmt(struct compiling *c, const node *n) +{ + int i; + stmt_ty ret; + asdl_seq *inner; + + REQ(n, with_stmt); + + /* process the with items inside-out */ + i = NCH(n) - 1; + /* the suite of the innermost with item is the suite of the with stmt */ + inner = ast_for_suite(c, CHILD(n, i)); + if (!inner) return NULL; + + for (;;) { + i -= 2; + ret = ast_for_with_item(c, CHILD(n, i), inner); + if (!ret) + return NULL; + /* was this the last item? */ + if (i == 1) + break; + /* if not, wrap the result so far in a new sequence */ + inner = asdl_seq_new(1, c->c_arena); + if (!inner) + return NULL; + asdl_seq_SET(inner, 0, ret); } - return With(context_expr, optional_vars, suite_seq, LINENO(n), - n->n_col_offset, c->c_arena); + + return ret; } static stmt_ty diff --git a/Python/graminit.c b/Python/graminit.c index 4c159bc..1bea8a6 100644 --- a/Python/graminit.c +++ b/Python/graminit.c @@ -911,42 +911,43 @@ static arc arcs_41_0[1] = { {99, 1}, }; static arc arcs_41_1[1] = { - {24, 2}, + {100, 2}, }; static arc arcs_41_2[2] = { - {100, 3}, - {25, 4}, + {30, 1}, + {25, 3}, }; static arc arcs_41_3[1] = { - {25, 4}, + {26, 4}, }; static arc arcs_41_4[1] = { - {26, 5}, -}; -static arc arcs_41_5[1] = { - {0, 5}, + {0, 4}, }; -static state states_41[6] = { +static state states_41[5] = { {1, arcs_41_0}, {1, arcs_41_1}, {2, arcs_41_2}, {1, arcs_41_3}, {1, arcs_41_4}, - {1, arcs_41_5}, }; static arc arcs_42_0[1] = { - {80, 1}, + {24, 1}, }; -static arc arcs_42_1[1] = { - {101, 2}, +static arc arcs_42_1[2] = { + {80, 2}, + {0, 1}, }; static arc arcs_42_2[1] = { - {0, 2}, + {101, 3}, +}; +static arc arcs_42_3[1] = { + {0, 3}, }; -static state states_42[3] = { +static state states_42[4] = { {1, arcs_42_0}, - {1, arcs_42_1}, + {2, arcs_42_1}, {1, arcs_42_2}, + {1, arcs_42_3}, }; static arc arcs_43_0[1] = { {102, 1}, @@ -1810,10 +1811,10 @@ static dfa dfas[81] = { "\000\000\000\000\000\000\000\000\000\000\000\100\000\000\000\000\000\000\000\000\000"}, {296, "try_stmt", 0, 13, states_40, "\000\000\000\000\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000\000\000"}, - {297, "with_stmt", 0, 6, states_41, + {297, "with_stmt", 0, 5, states_41, "\000\000\000\000\000\000\000\000\000\000\000\000\010\000\000\000\000\000\000\000\000"}, - {298, "with_var", 0, 3, states_42, - "\000\000\000\000\000\000\000\000\000\000\001\000\000\000\000\000\000\000\000\000\000"}, + {298, "with_item", 0, 4, states_42, + "\000\040\040\200\000\000\000\000\000\040\000\000\000\040\004\000\000\103\050\037\000"}, {299, "except_clause", 0, 5, states_43, "\000\000\000\000\000\000\000\000\000\000\000\000\100\000\000\000\000\000\000\000\000"}, {300, "suite", 0, 5, states_44, |