diff --git twisted/python/compat.py twisted/python/compat.py index 7a56f86..cf4ffdd 100644 --- twisted/python/compat.py +++ twisted/python/compat.py @@ -357,6 +357,56 @@ integer. """ + +if _PY3: + def chr_(i): + if isinstance(i, int): + if i > 255: + raise ValueError("chr() arg not in range(256)") + return chr(i).encode("latin1") + else: + raise TypeError("an integer is required") +else: + # We need to emulate 2.x? THIS. IS. 2.X! + def chr_(i): + return chr(i) + +chr_.__doc__ = """ +Duplicate the behavior of 2x chr in 3x. + +The Python 2.x built-in chr converted integers in [0, 255] to the +one-character byte strings containing the character with that ASCII encoded +value. + +The Python 3.x chr instead takes integers in the range [0, 1114111], and +converts them to one-character Unicode strings containing the character +with that code-point. + +The chr_ in this function duplicates 2.x behavior on both 2.x and 3.x. + +See these extracts from the Python manual for details. + +Python 2.x +---------- +chr: +"Return a string of one character whose ASCII code is the integer i. For +example, chr(97) returns the string 'a'. This is the inverse of ord(). The +argument must be in the range [0..255], inclusive; ValueError will be raised if +i is outside that range. See also unichr()." +http://docs.python.org/library/functions.html#chr + +Python 3.x +---------- +chr: +"Return the string representing a character whose Unicode codepoint is the +integer i. For example, chr(97) returns the string 'a'. This is the inverse of +ord(). The valid range for the argument is from 0 through 1,114,111 (0x10FFFF +in base 16). ValueError will be raised if i is outside that range." +http://docs.python.org/py3k/library/functions.html#chr +""" + + + __all__ = [ "reraise", "execfile", @@ -370,4 +420,5 @@ __all__ = [ "unicode", "iterbytes", "intToBytes", + "chr_" ] diff --git twisted/test/test_compat.py twisted/test/test_compat.py index b408153..3121b3c 100644 --- twisted/test/test_compat.py +++ twisted/test/test_compat.py @@ -16,6 +16,7 @@ from twisted.python.compat import set, frozenset, reduce, execfile, _PY3 from twisted.python.compat import comparable, cmp, nativeString from twisted.python.compat import unicode as unicodeCompat from twisted.python.compat import reraise, NativeStringIO, iterbytes, intToBytes +from twisted.python.compat import chr_ from twisted.python.filepath import FilePath @@ -538,3 +539,90 @@ class Python3BytesTests(unittest.SynchronousTestCase): ASCII-encoded string representation of the number. """ self.assertEqual(intToBytes(213), b"213") + + + +class chr_Tests(unittest.SynchronousTestCase): + """ + Tests for L{compat.chr_}. + + L{compat.chr_} should emulate the Python 2.x built-in chr which had + these key characteristics: + -Accepted an integer in [0, 255]. + -Returned a bytestring containing the character encoded to that + integer under ASCII. + -Raised a ValueError in response to any integer outside that range. + -Raised a TypeError in response to any other input. + """ + # A sampling of ASCII characters, which chr_ should accept. + _ASCIIEncodedValues = [0, 1, 103, 104, 126, 127, 128, 254, 255] + _ASCIICharacters = [b"\x00", b"\x01", b"g", b"h", b"~", b"\x7f", b"\x80", b"\xfe", b"\xff"] + # And here is a sampling of things that chr_ should NOT accept. + _negativeIntegers = [-10, -1] + _integersOver255 = [256, 257, 500, 1000, 10000, 60000, 65534, 65535] + _integersOver65535 = [65536, 65537, 100000] + _bytestringASCIICharacters = [b"a", b"\x15"] + _UnicodeCharacters = [u"b", u"\xeff", u"\xfffe", u"\xffff"] + _UnicodeCharactersOver65535 = [u"\x10000", u"\x10001"] + _nonIntegersNotCharacters = [2.3, dict()] + + def test_chr_Accepts(self): + """ + L{compat.chr_} accepts integers in [0, 255] and returns the + corresponding character in an ASCII-encoded bytestring. + """ + for (encodedValue, bytestringCharacter) in zip( + self._ASCIIEncodedValues, self._ASCIICharacters): + # Deliberately leak any exceptions; failing the test with ERROR. + ret = chr_(encodedValue) + self.assertIsInstance(ret, bytes) + self.assertEqual(ret, bytestringCharacter) + + def _assert_chr_Rejects(self, invalidInput, exceptionToRejectWith): + """Convenience function. map assertRaises across invalidInput.""" + for x in invalidInput: + self.assertRaises(exceptionToRejectWith, chr_, x) + + def test_chr_RejectsNegativeIntegers(self): + """ + L{compat.chr_} rejects negative integers with ValueError. + """ + self._assert_chr_Rejects(self._negativeIntegers, ValueError) + + def test_chr_RejectsIntegersOver255(self): + """ + L{compat.chr_} rejects integers over 255 with ValueError. + """ + self._assert_chr_Rejects(self._integersOver255, ValueError) + + def test_chr_RejectsIntegersOver65535(self): + """ + L{compat.chr_} rejects integers over 65535 with ValueError. + """ + self._assert_chr_Rejects(self._integersOver65535, ValueError) + + def test_chr_RejectsBytestringASCIICharacters(self): + """ + L{compat.chr_} rejects ASCII-encoded bytestrings with TypeError. + """ + self._assert_chr_Rejects(self._bytestringASCIICharacters, TypeError) + + def test_chr_RejectsUnicodeCharacters(self): + """ + L{compat.chr_} rejects Unicode strings with TypeError. + """ + self._assert_chr_Rejects(self._UnicodeCharacters, TypeError) + + def test_chr_RejectsUnicodeCharactersOver65535(self): + """ + L{compat.chr_} rejects Unicode strings with codepoints over 65535 with + TypeError. + """ + self._assert_chr_Rejects(self._UnicodeCharactersOver65535, TypeError) + + def test_chr_RejectsNonIntegersNonCharacters(self): + """ + L{compat.chr_} rejects any other odd thing you give it, like a dict, + with TypeError. + """ + self._assert_chr_Rejects(self._nonIntegersNotCharacters, TypeError) diff --git twisted/topfiles/6070.misc twisted/topfiles/6070.misc new file mode 100644 index 0000000..e69de29