New submission from Anders Rundgren: ECMA has in their latest release defined that JSON elements must be ordered during serialization. This is easy to accomplish using Python's OrderedDict. What is less trivial is that numbers have to be formatted in a certain way as well. I have tested 100 millions specific and random values and found out that Python 3.5.1 is mathematically identical to ES6/V8 but has some differences in formatting:
IEEE Double ECMAScript 6/V8 Python 3.5.1 c43211ede4974a35, -333333333333333300000, -3.333333333333333e+20 c3fce97ca0f21056, -33333333333333336000, -3.3333333333333336e+19 c3c7213080c1a6ac, -3333333333333334000, -3.333333333333334e+18 c39280f39a348556, -333333333333333400, -3.333333333333334e+17 c35d9b1f5d20d557, -33333333333333340, -3.333333333333334e+16 c327af4c4a80aaac, -3333333333333334, -3333333333333334.0 bf0179ec9cbd821e, -0.000033333333333333335, -3.3333333333333335e-05 becbf647612f3696, -0.0000033333333333333333, -3.3333333333333333e-06 4024000000000000, 10, 10.0 0000000000000000, 0, 0.0 4014000000000000, 5, 5.0 3f0a36e2eb1c432d, 0.00005, 5e-05 3ed4f8b588e368f1, 0.000005, 5e-06 3ea0c6f7a0b5ed8d, 5e-7, 5e-07 Why could this be important? https://github.com/Microsoft/ChakraCore/issues/149 # Python test program import binascii import struct import json f = open('c:\\es6\\numbers\\es6testfile100m.txt','rb') l = 0; string = ''; while True: byte = f.read(1); if len(byte) == 0: exit(0) if byte == b'\n': l = l + 1; i = string.find(',') if i <= 0 or i >= len(string) - 1: print('Bad string: ' + str(i)) exit(0) hex = string[:i] while len(hex) < 16: hex = '0' + hex o = dict() o['double'] = struct.unpack('>d',binascii.a2b_hex(hex))[0] py3Double = json.dumps(o)[11:-1] es6Double = string[i + 1:] if es6Double != py3Double: es6Dpos = es6Double.find('.') py3Dpos = py3Double.find('.') es6Epos = es6Double.find('e') py3Epos = py3Double.find('e') if py3Epos > 0: py3Exp = int(py3Double[py3Epos + 1:]) if es6Dpos < 0 and py3Dpos > 0: if es6Epos < 0 and py3Epos > 0: py3New = py3Double[:py3Dpos] + py3Double[py3Dpos + 1:py3Epos - len(py3Double)] q = py3Exp - py3Epos + py3Dpos while q >= 0: py3New += '0' q -= 1 if py3New != es6Double: print('E1: ' + py3New) exit(0) elif py3Epos < 0: py3New = py3Double[:-2] if py3New != es6Double: print('E2: ' + py3New) exit(0) else: print (error + hex + '#' + es6Double + '#' + py3Double) exit(0) elif es6Dpos > 0 and py3Dpos > 0 and py3Epos > 0 and es6Epos < 0: py3New = py3Double[py3Dpos - 1:py3Dpos] + py3Double[py3Dpos + 1:py3Epos - len(py3Double)] q = py3Exp + 1 while q < 0: q += 1 py3New = '0' + py3New py3New = py3Double[0:py3Dpos - 1] + '0.' + py3New if py3New != es6Double: print('E3: ' + py3New + '#' + es6Double) exit(0) elif es6Dpos == py3Dpos and py3Epos > 0 and es6Epos > 0: py3New = py3Double[:py3Epos + 2] + str(abs(py3Exp)) if py3New != es6Double: print('E4: ' + py3New + '#' + es6Double) exit(0) elif es6Dpos > 0 and py3Dpos < 0 and py3Epos > 0 and es6Epos < 0: py3New = py3Double[:py3Epos - len(py3Double)] q = py3Exp + 1 while q < 0: q += 1 py3New = '0' + py3New py3New = '0.' + py3New if py3New != es6Double: print('E5: ' + py3New + '#' + es6Double) exit(0) else: print ('Unexpected: ' + hex + '#' + es6Double + '#' + py3Double) exit(0) string = '' if l % 10000 == 0: print(l) else: string += byte.decode(encoding='UTF-8') ---------- components: Interpreter Core messages: 259105 nosy: anders.rundgren....@gmail.com priority: normal severity: normal status: open title: Make number serialization ES6/V8 compatible type: enhancement versions: Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue26229> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
