Patch #1491866: change the complex() constructor to allow parthensized forms.…

Patch #1491866: change the complex() constructor to allow parthensized forms. This means complex(repr(x)) now works instead of raising a ValueError.

Lib/test/test_complex.py

@@ -215,6 +215,8 @@ class ComplexTest(unittest.TestCase):
         self.assertAlmostEqual(complex(),  0)
         self.assertAlmostEqual(complex("-1"), -1)
         self.assertAlmostEqual(complex("+1"), +1)
+        self.assertAlmostEqual(complex("(1+2j)"), 1+2j)
+        self.assertAlmostEqual(complex("(1.3+2.2j)"), 1.3+2.2j)
 
         class complex2(complex): pass
         self.assertAlmostEqual(complex(complex2(1+1j)), 1+1j)
@@ -244,12 +246,17 @@ class ComplexTest(unittest.TestCase):
         self.assertRaises(ValueError, complex, "")
         self.assertRaises(TypeError, complex, None)
         self.assertRaises(ValueError, complex, "\0")
+        self.assertRaises(ValueError, complex, "3\09")
         self.assertRaises(TypeError, complex, "1", "2")
         self.assertRaises(TypeError, complex, "1", 42)
         self.assertRaises(TypeError, complex, 1, "2")
         self.assertRaises(ValueError, complex, "1+")
         self.assertRaises(ValueError, complex, "1+1j+1j")
         self.assertRaises(ValueError, complex, "--")
+        self.assertRaises(ValueError, complex, "(1+2j")
+        self.assertRaises(ValueError, complex, "1+2j)")
+        self.assertRaises(ValueError, complex, "1+(2j)")
+        self.assertRaises(ValueError, complex, "(1+2j)123")
         if test_support.have_unicode:
             self.assertRaises(ValueError, complex, unicode("1"*500))
             self.assertRaises(ValueError, complex, unicode("x"))
@@ -312,6 +319,11 @@ class ComplexTest(unittest.TestCase):
 
         self.assertNotEqual(repr(-(1+0j)), '(-1+-0j)')
 
+        self.assertEqual(1-6j,complex(repr(1-6j)))
+        self.assertEqual(1+6j,complex(repr(1+6j)))
+        self.assertEqual(-6j,complex(repr(-6j)))
+        self.assertEqual(6j,complex(repr(6j)))
+
     def test_neg(self):
         self.assertEqual(-(1+6j), -1-6j)
 

Misc/NEWS

@@ -12,6 +12,10 @@ What's New in Python 2.6 alpha 1?
 Core and builtins
 -----------------
 
+- Patch #1491866: change the complex() constructor to allow parthensized
+  forms. This means complex(repr(x)) now works instead of raising a
+  ValueError.
+
 - Patch #703779: unset __file__ in __main__ after running a file. This
   makes the filenames the warning module prints much more sensible when
   a PYTHONSTARTUP file is used.

Objects/complexobject.c

@@ -672,7 +672,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 	const char *s, *start;
 	char *end;
 	double x=0.0, y=0.0, z;
-	int got_re=0, got_im=0, done=0;
+	int got_re=0, got_im=0, got_bracket=0, done=0;
 	int digit_or_dot;
 	int sw_error=0;
 	int sign;
@@ -712,10 +712,17 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 	start = s;
 	while (*s && isspace(Py_CHARMASK(*s)))
 		s++;
-	if (s[0] == '\0') {
+    if (s[0] == '\0') {
 		PyErr_SetString(PyExc_ValueError,
 				"complex() arg is an empty string");
 		return NULL;
+    }
+	if (s[0] == '(') {
+		/* Skip over possible bracket from repr(). */
+		got_bracket = 1;
+		s++;
+		while (*s && isspace(Py_CHARMASK(*s)))
+			s++;
 	}
 
 	z = -1.0;
@@ -734,13 +741,26 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 			if(!done) sw_error=1;
 			break;
 
+		case ')':
+			if (!got_bracket || !(got_re || got_im)) {
+				sw_error=1;
+				break;
+			}
+			got_bracket=0;
+			done=1;
+			s++;
+			while (*s && isspace(Py_CHARMASK(*s)))
+				s++;
+			if (*s) sw_error=1;
+			break;
+
 		case '-':
 			sign = -1;
 				/* Fallthrough */
 		case '+':
 			if (done)  sw_error=1;
 			s++;
-			if  (  *s=='\0'||*s=='+'||*s=='-'  ||
+			if  (  *s=='\0'||*s=='+'||*s=='-'||*s==')'||
 			       isspace(Py_CHARMASK(*s))  )  sw_error=1;
 			break;
 
@@ -766,7 +786,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 			if (isspace(Py_CHARMASK(*s))) {
 				while (*s && isspace(Py_CHARMASK(*s)))
 					s++;
-				if (s[0] != '\0')
+				if (*s && *s != ')')
 					sw_error=1;
 				else
 					done = 1;
@@ -812,7 +832,7 @@ complex_subtype_from_string(PyTypeObject *type, PyObject *v)
 
 	} while (s - start < len && !sw_error);
 
-	if (sw_error) {
+	if (sw_error || got_bracket) {
 		PyErr_SetString(PyExc_ValueError,
 				"complex() arg is a malformed string");
 		return NULL;