"""Unit tests for memory-based file-like objects. StringIO -- for unicode strings BytesIO -- for bytes """ import unittest from test import support import io import _pyio as pyio import pickle class MemorySeekTestMixin: def testInit(self): buf = self.buftype("1234567890") bytesIo = self.ioclass(buf) def testRead(self): buf = self.buftype("1234567890") bytesIo = self.ioclass(buf) self.assertEqual(buf[:1], bytesIo.read(1)) self.assertEqual(buf[1:5], bytesIo.read(4)) self.assertEqual(buf[5:], bytesIo.read(900)) self.assertEqual(self.EOF, bytesIo.read()) def testReadNoArgs(self): buf = self.buftype("1234567890") bytesIo = self.ioclass(buf) self.assertEqual(buf, bytesIo.read()) self.assertEqual(self.EOF, bytesIo.read()) def testSeek(self): buf = self.buftype("1234567890") bytesIo = self.ioclass(buf) bytesIo.read(5) bytesIo.seek(0) self.assertEqual(buf, bytesIo.read()) bytesIo.seek(3) self.assertEqual(buf[3:], bytesIo.read()) self.assertRaises(TypeError, bytesIo.seek, 0.0) def testTell(self): buf = self.buftype("1234567890") bytesIo = self.ioclass(buf) self.assertEqual(0, bytesIo.tell()) bytesIo.seek(5) self.assertEqual(5, bytesIo.tell()) bytesIo.seek(10000) self.assertEqual(10000, bytesIo.tell()) class MemoryTestMixin: def test_detach(self): buf = self.ioclass() self.assertRaises(self.UnsupportedOperation, buf.detach) def write_ops(self, f, t): self.assertEqual(f.write(t("blah.")), 5) self.assertEqual(f.seek(0), 0) self.assertEqual(f.write(t("Hello.")), 6) self.assertEqual(f.tell(), 6) self.assertEqual(f.seek(5), 5) self.assertEqual(f.tell(), 5) self.assertEqual(f.write(t(" world\n\n\n")), 9) self.assertEqual(f.seek(0), 0) self.assertEqual(f.write(t("h")), 1) self.assertEqual(f.truncate(12), 12) self.assertEqual(f.tell(), 1) def test_write(self): buf = self.buftype("hello world\n") memio = self.ioclass(buf) self.write_ops(memio, self.buftype) self.assertEqual(memio.getvalue(), buf) memio = self.ioclass() self.write_ops(memio, self.buftype) self.assertEqual(memio.getvalue(), buf) self.assertRaises(TypeError, memio.write, None) memio.close() self.assertRaises(ValueError, memio.write, self.buftype("")) def test_writelines(self): buf = self.buftype("1234567890") memio = self.ioclass() self.assertEqual(memio.writelines([buf] * 100), None) self.assertEqual(memio.getvalue(), buf * 100) memio.writelines([]) self.assertEqual(memio.getvalue(), buf * 100) memio = self.ioclass() self.assertRaises(TypeError, memio.writelines, [buf] + [1]) self.assertEqual(memio.getvalue(), buf) self.assertRaises(TypeError, memio.writelines, None) memio.close() self.assertRaises(ValueError, memio.writelines, []) def test_writelines_error(self): memio = self.ioclass() def error_gen(): yield self.buftype('spam') raise KeyboardInterrupt self.assertRaises(KeyboardInterrupt, memio.writelines, error_gen()) def test_truncate(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertRaises(ValueError, memio.truncate, -1) memio.seek(6) self.assertEqual(memio.truncate(), 6) self.assertEqual(memio.getvalue(), buf[:6]) self.assertEqual(memio.truncate(4), 4) self.assertEqual(memio.getvalue(), buf[:4]) self.assertEqual(memio.tell(), 6) memio.seek(0, 2) memio.write(buf) self.assertEqual(memio.getvalue(), buf[:4] + buf) pos = memio.tell() self.assertEqual(memio.truncate(None), pos) self.assertEqual(memio.tell(), pos) self.assertRaises(TypeError, memio.truncate, '0') memio.close() self.assertRaises(ValueError, memio.truncate, 0) def test_init(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.getvalue(), buf) memio = self.ioclass(None) self.assertEqual(memio.getvalue(), self.EOF) memio.__init__(buf * 2) self.assertEqual(memio.getvalue(), buf * 2) memio.__init__(buf) self.assertEqual(memio.getvalue(), buf) self.assertRaises(TypeError, memio.__init__, []) def test_read(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.read(0), self.EOF) self.assertEqual(memio.read(1), buf[:1]) self.assertEqual(memio.read(4), buf[1:5]) self.assertEqual(memio.read(900), buf[5:]) self.assertEqual(memio.read(), self.EOF) memio.seek(0) self.assertEqual(memio.read(), buf) self.assertEqual(memio.read(), self.EOF) self.assertEqual(memio.tell(), 10) memio.seek(0) self.assertEqual(memio.read(-1), buf) memio.seek(0) self.assertEqual(type(memio.read()), type(buf)) memio.seek(100) self.assertEqual(type(memio.read()), type(buf)) memio.seek(0) self.assertEqual(memio.read(None), buf) self.assertRaises(TypeError, memio.read, '') memio.close() self.assertRaises(ValueError, memio.read) def test_readline(self): buf = self.buftype("1234567890\n") memio = self.ioclass(buf * 2) self.assertEqual(memio.readline(0), self.EOF) self.assertEqual(memio.readline(), buf) self.assertEqual(memio.readline(), buf) self.assertEqual(memio.readline(), self.EOF) memio.seek(0) self.assertEqual(memio.readline(5), buf[:5]) self.assertEqual(memio.readline(5), buf[5:10]) self.assertEqual(memio.readline(5), buf[10:15]) memio.seek(0) self.assertEqual(memio.readline(-1), buf) memio.seek(0) self.assertEqual(memio.readline(0), self.EOF) buf = self.buftype("1234567890\n") memio = self.ioclass((buf * 3)[:-1]) self.assertEqual(memio.readline(), buf) self.assertEqual(memio.readline(), buf) self.assertEqual(memio.readline(), buf[:-1]) self.assertEqual(memio.readline(), self.EOF) memio.seek(0) self.assertEqual(type(memio.readline()), type(buf)) self.assertEqual(memio.readline(), buf) self.assertRaises(TypeError, memio.readline, '') memio.close() self.assertRaises(ValueError, memio.readline) def test_readlines(self): buf = self.buftype("1234567890\n") memio = self.ioclass(buf * 10) self.assertEqual(memio.readlines(), [buf] * 10) memio.seek(5) self.assertEqual(memio.readlines(), [buf[5:]] + [buf] * 9) memio.seek(0) self.assertEqual(memio.readlines(15), [buf] * 2) memio.seek(0) self.assertEqual(memio.readlines(-1), [buf] * 10) memio.seek(0) self.assertEqual(memio.readlines(0), [buf] * 10) memio.seek(0) self.assertEqual(type(memio.readlines()[0]), type(buf)) memio.seek(0) self.assertEqual(memio.readlines(None), [buf] * 10) self.assertRaises(TypeError, memio.readlines, '') memio.close() self.assertRaises(ValueError, memio.readlines) def test_iterator(self): buf = self.buftype("1234567890\n") memio = self.ioclass(buf * 10) self.assertEqual(iter(memio), memio) self.assertTrue(hasattr(memio, '__iter__')) self.assertTrue(hasattr(memio, '__next__')) i = 0 for line in memio: self.assertEqual(line, buf) i += 1 self.assertEqual(i, 10) memio.seek(0) i = 0 for line in memio: self.assertEqual(line, buf) i += 1 self.assertEqual(i, 10) memio = self.ioclass(buf * 2) memio.close() self.assertRaises(ValueError, memio.__next__) def test_getvalue(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.getvalue(), buf) memio.read() self.assertEqual(memio.getvalue(), buf) self.assertEqual(type(memio.getvalue()), type(buf)) memio = self.ioclass(buf * 1000) self.assertEqual(memio.getvalue()[-3:], self.buftype("890")) memio = self.ioclass(buf) memio.close() self.assertRaises(ValueError, memio.getvalue) def test_seek(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) memio.read(5) self.assertRaises(ValueError, memio.seek, -1) self.assertRaises(ValueError, memio.seek, 1, -1) self.assertRaises(ValueError, memio.seek, 1, 3) self.assertEqual(memio.seek(0), 0) self.assertEqual(memio.seek(0, 0), 0) self.assertEqual(memio.read(), buf) self.assertEqual(memio.seek(3), 3) self.assertEqual(memio.seek(0, 1), 3) self.assertEqual(memio.read(), buf[3:]) self.assertEqual(memio.seek(len(buf)), len(buf)) self.assertEqual(memio.read(), self.EOF) memio.seek(len(buf) + 1) self.assertEqual(memio.read(), self.EOF) self.assertEqual(memio.seek(0, 2), len(buf)) self.assertEqual(memio.read(), self.EOF) memio.close() self.assertRaises(ValueError, memio.seek, 0) def test_overseek(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.seek(len(buf) + 1), 11) self.assertEqual(memio.read(), self.EOF) self.assertEqual(memio.tell(), 11) self.assertEqual(memio.getvalue(), buf) memio.write(self.EOF) self.assertEqual(memio.getvalue(), buf) memio.write(buf) self.assertEqual(memio.getvalue(), buf + self.buftype('\0') + buf) def test_tell(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.tell(), 0) memio.seek(5) self.assertEqual(memio.tell(), 5) memio.seek(10000) self.assertEqual(memio.tell(), 10000) memio.close() self.assertRaises(ValueError, memio.tell) def test_flush(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.flush(), None) def test_flags(self): memio = self.ioclass() self.assertEqual(memio.writable(), True) self.assertEqual(memio.readable(), True) self.assertEqual(memio.seekable(), True) self.assertEqual(memio.isatty(), False) self.assertEqual(memio.closed, False) memio.close() self.assertRaises(ValueError, memio.writable) self.assertRaises(ValueError, memio.readable) self.assertRaises(ValueError, memio.seekable) self.assertRaises(ValueError, memio.isatty) self.assertEqual(memio.closed, True) def test_subclassing(self): buf = self.buftype("1234567890") def test1(): class MemIO(self.ioclass): pass m = MemIO(buf) return m.getvalue() def test2(): class MemIO(self.ioclass): def __init__(me, a, b): self.ioclass.__init__(me, a) m = MemIO(buf, None) return m.getvalue() self.assertEqual(test1(), buf) self.assertEqual(test2(), buf) def test_instance_dict_leak(self): # Test case for issue #6242. # This will be caught by regrtest.py -R if this leak. for _ in range(100): memio = self.ioclass() memio.foo = 1 def test_pickling(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) memio.foo = 42 memio.seek(2) class PickleTestMemIO(self.ioclass): def __init__(me, initvalue, foo): self.ioclass.__init__(me, initvalue) me.foo = foo # __getnewargs__ is undefined on purpose. This checks that PEP 307 # is used to provide pickling support. # Pickle expects the class to be on the module level. Here we use a # little hack to allow the PickleTestMemIO class to derive from # self.ioclass without having to define all combinations explictly on # the module-level. import __main__ PickleTestMemIO.__module__ = '__main__' __main__.PickleTestMemIO = PickleTestMemIO submemio = PickleTestMemIO(buf, 80) submemio.seek(2) # We only support pickle protocol 2 and onward since we use extended # __reduce__ API of PEP 307 to provide pickling support. for proto in range(2, pickle.HIGHEST_PROTOCOL): for obj in (memio, submemio): obj2 = pickle.loads(pickle.dumps(obj, protocol=proto)) self.assertEqual(obj.getvalue(), obj2.getvalue()) self.assertEqual(obj.__class__, obj2.__class__) self.assertEqual(obj.foo, obj2.foo) self.assertEqual(obj.tell(), obj2.tell()) obj2.close() self.assertRaises(ValueError, pickle.dumps, obj2, proto) del __main__.PickleTestMemIO class BytesIOMixin: def test_getbuffer(self): memio = self.ioclass(b"1234567890") buf = memio.getbuffer() self.assertEqual(bytes(buf), b"1234567890") memio.seek(5) buf = memio.getbuffer() self.assertEqual(bytes(buf), b"1234567890") # Trying to change the size of the BytesIO while a buffer is exported # raises a BufferError. self.assertRaises(BufferError, memio.write, b'x' * 100) self.assertRaises(BufferError, memio.truncate) # Mutating the buffer updates the BytesIO buf[3:6] = b"abc" self.assertEqual(bytes(buf), b"123abc7890") self.assertEqual(memio.getvalue(), b"123abc7890") # After the buffer gets released, we can resize the BytesIO again del buf support.gc_collect() memio.truncate() class PyBytesIOTest(MemoryTestMixin, MemorySeekTestMixin, BytesIOMixin, unittest.TestCase): UnsupportedOperation = pyio.UnsupportedOperation @staticmethod def buftype(s): return s.encode("ascii") ioclass = pyio.BytesIO EOF = b"" def test_read1(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertRaises(TypeError, memio.read1) self.assertEqual(memio.read(), buf) def test_readinto(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) b = bytearray(b"hello") self.assertEqual(memio.readinto(b), 5) self.assertEqual(b, b"12345") self.assertEqual(memio.readinto(b), 5) self.assertEqual(b, b"67890") self.assertEqual(memio.readinto(b), 0) self.assertEqual(b, b"67890") b = bytearray(b"hello world") memio.seek(0) self.assertEqual(memio.readinto(b), 10) self.assertEqual(b, b"1234567890d") b = bytearray(b"") memio.seek(0) self.assertEqual(memio.readinto(b), 0) self.assertEqual(b, b"") self.assertRaises(TypeError, memio.readinto, '') import array a = array.array('b', b"hello world") memio = self.ioclass(buf) memio.readinto(a) self.assertEqual(a.tobytes(), b"1234567890d") memio.close() self.assertRaises(ValueError, memio.readinto, b) memio = self.ioclass(b"123") b = bytearray() memio.seek(42) memio.readinto(b) self.assertEqual(b, b"") def test_relative_seek(self): buf = self.buftype("1234567890") memio = self.ioclass(buf) self.assertEqual(memio.seek(-1, 1), 0) self.assertEqual(memio.seek(3, 1), 3) self.assertEqual(memio.seek(-4, 1), 0) self.assertEqual(memio.seek(-1, 2), 9) self.assertEqual(memio.seek(1, 1), 10) self.assertEqual(memio.seek(1, 2), 11) memio.seek(-3, 2) self.assertEqual(memio.read(), buf[-3:]) memio.seek(0) memio.seek(1, 1) self.assertEqual(memio.read(), buf[1:]) def test_unicode(self): memio = self.ioclass() self.assertRaises(TypeError, self.ioclass, "1234567890") self.assertRaises(TypeError, memio.write, "1234567890") self.assertRaises(TypeError, memio.writelines, ["1234567890"]) def test_bytes_array(self): buf = b"1234567890" import array a = array.array('b', list(buf)) memio = self.ioclass(a) self.assertEqual(memio.getvalue(), buf) self.assertEqual(memio.write(a), 10) self.assertEqual(memio.getvalue(), buf) def test_issue5449(self): buf = self.buftype("1234567890") self.ioclass(initial_bytes=buf) self.assertRaises(TypeError, self.ioclass, buf, foo=None) class TextIOTestMixin: def test_newlines_property(self): memio = self.ioclass(newline=None) # The C StringIO decodes newlines in write() calls, but the Python # implementation only does when reading. This function forces them to # be decoded for testing. def force_decode(): memio.seek(0) memio.read() self.assertEqual(memio.newlines, None) memio.write("a\n") force_decode() self.assertEqual(memio.newlines, "\n") memio.write("b\r\n") force_decode() self.assertEqual(memio.newlines, ("\n", "\r\n")) memio.write("c\rd") force_decode() self.assertEqual(memio.newlines, ("\r", "\n", "\r\n")) def test_relative_seek(self): memio = self.ioclass() self.assertRaises(OSError, memio.seek, -1, 1) self.assertRaises(OSError, memio.seek, 3, 1) self.assertRaises(OSError, memio.seek, -3, 1) self.assertRaises(OSError, memio.seek, -1, 2) self.assertRaises(OSError, memio.seek, 1, 1) self.assertRaises(OSError, memio.seek, 1, 2) def test_textio_properties(self): memio = self.ioclass() # These are just dummy values but we nevertheless check them for fear # of unexpected breakage. self.assertIsNone(memio.encoding) self.assertIsNone(memio.errors) self.assertFalse(memio.line_buffering) def test_newline_none(self): # newline=None memio = self.ioclass("a\nb\r\nc\rd", newline=None) self.assertEqual(list(memio), ["a\n", "b\n", "c\n", "d"]) memio.seek(0) self.assertEqual(memio.read(1), "a") self.assertEqual(memio.read(2), "\nb") self.assertEqual(memio.read(2), "\nc") self.assertEqual(memio.read(1), "\n") memio = self.ioclass(newline=None) self.assertEqual(2, memio.write("a\n")) self.assertEqual(3, memio.write("b\r\n")) self.assertEqual(3, memio.write("c\rd")) memio.seek(0) self.assertEqual(memio.read(), "a\nb\nc\nd") memio = self.ioclass("a\r\nb", newline=None) self.assertEqual(memio.read(3), "a\nb") def test_newline_empty(self): # newline="" memio = self.ioclass("a\nb\r\nc\rd", newline="") self.assertEqual(list(memio), ["a\n", "b\r\n", "c\r", "d"]) memio.seek(0) self.assertEqual(memio.read(4), "a\nb\r") self.assertEqual(memio.read(2), "\nc") self.assertEqual(memio.read(1), "\r") memio = self.ioclass(newline="") self.assertEqual(2, memio.write("a\n")) self.assertEqual(2, memio.write("b\r")) self.assertEqual(2, memio.write("\nc")) self.assertEqual(2, memio.write("\rd")) memio.seek(0) self.assertEqual(list(memio), ["a\n", "b\r\n", "c\r", "d"]) def test_newline_lf(self): # newline="\n" memio = self.ioclass("a\nb\r\nc\rd") self.assertEqual(list(memio), ["a\n", "b\r\n", "c\rd"]) def test_newline_cr(self): # newline="\r" memio = self.ioclass("a\nb\r\nc\rd", newline="\r") self.assertEqual(memio.read(), "a\rb\r\rc\rd") memio.seek(0) self.assertEqual(list(memio), ["a\r", "b\r", "\r", "c\r", "d"]) def test_newline_crlf(self): # newline="\r\n" memio = self.ioclass("a\nb\r\nc\rd", newline="\r\n") self.assertEqual(memio.read(), "a\r\nb\r\r\nc\rd") memio.seek(0) self.assertEqual(list(memio), ["a\r\n", "b\r\r\n", "c\rd"]) def test_issue5265(self): # StringIO can duplicate newlines in universal newlines mode memio = self.ioclass("a\r\nb\r\n", newline=None) self.assertEqual(memio.read(5), "a\nb\n") def test_newline_argument(self): self.assertRaises(TypeError, self.ioclass, newline=b"\n") self.assertRaises(ValueError, self.ioclass, newline="error") # These should not raise an error for newline in (None, "", "\n", "\r", "\r\n"): self.ioclass(newline=newline) class PyStringIOTest(MemoryTestMixin, MemorySeekTestMixin, TextIOTestMixin, unittest.TestCase): buftype = str ioclass = pyio.StringIO UnsupportedOperation = pyio.UnsupportedOperation EOF = "" def test_lone_surrogates(self): # Issue #20424 memio = self.ioclass('\ud800') self.assertEqual(memio.read(), '\ud800') memio = self.ioclass() memio.write('\ud800') self.assertEqual(memio.getvalue(), '\ud800') class PyStringIOPickleTest(TextIOTestMixin, unittest.TestCase): """Test if pickle restores properly the internal state of StringIO. """ buftype = str UnsupportedOperation = pyio.UnsupportedOperation EOF = "" class ioclass(pyio.StringIO): def __new__(cls, *args, **kwargs): return pickle.loads(pickle.dumps(pyio.StringIO(*args, **kwargs))) def __init__(self, *args, **kwargs): pass class CBytesIOTest(PyBytesIOTest): ioclass = io.BytesIO UnsupportedOperation = io.UnsupportedOperation def test_getstate(self): memio = self.ioclass() state = memio.__getstate__() self.assertEqual(len(state), 3) bytearray(state[0]) # Check if state[0] supports the buffer interface. self.assertIsInstance(state[1], int) self.assertTrue(isinstance(state[2], dict) or state[2] is None) memio.close() self.assertRaises(ValueError, memio.__getstate__) def test_setstate(self): # This checks whether __setstate__ does proper input validation. memio = self.ioclass() memio.__setstate__((b"no error", 0, None)) memio.__setstate__((bytearray(b"no error"), 0, None)) memio.__setstate__((b"no error", 0, {'spam': 3})) self.assertRaises(ValueError, memio.__setstate__, (b"", -1, None)) self.assertRaises(TypeError, memio.__setstate__, ("unicode", 0, None)) self.assertRaises(TypeError, memio.__setstate__, (b"", 0.0, None)) self.assertRaises(TypeError, memio.__setstate__, (b"", 0, 0)) self.assertRaises(TypeError, memio.__setstate__, (b"len-test", 0)) self.assertRaises(TypeError, memio.__setstate__) self.assertRaises(TypeError, memio.__setstate__, 0) memio.close() self.assertRaises(ValueError, memio.__setstate__, (b"closed", 0, None)) check_sizeof = support.check_sizeof @support.cpython_only def test_sizeof(self): basesize = support.calcobjsize('P2nN2Pn') check = self.check_sizeof self.assertEqual(object.__sizeof__(io.BytesIO()), basesize) check(io.BytesIO(), basesize ) check(io.BytesIO(b'a'), basesize + 1 + 1 ) check(io.BytesIO(b'a' * 1000), basesize + 1000 + 1 ) class CStringIOTest(PyStringIOTest): ioclass = io.StringIO UnsupportedOperation = io.UnsupportedOperation # XXX: For the Python version of io.StringIO, this is highly # dependent on the encoding used for the underlying buffer. def test_widechar(self): buf = self.buftype("\U0002030a\U00020347") memio = self.ioclass(buf) self.assertEqual(memio.getvalue(), buf) self.assertEqual(memio.write(buf), len(buf)) self.assertEqual(memio.tell(), len(buf)) self.assertEqual(memio.getvalue(), buf) self.assertEqual(memio.write(buf), len(buf)) self.assertEqual(memio.tell(), len(buf) * 2) self.assertEqual(memio.getvalue(), buf + buf) def test_getstate(self): memio = self.ioclass() state = memio.__getstate__() self.assertEqual(len(state), 4) self.assertIsInstance(state[0], str) self.assertIsInstance(state[1], str) self.assertIsInstance(state[2], int) self.assertTrue(isinstance(state[3], dict) or state[3] is None) memio.close() self.assertRaises(ValueError, memio.__getstate__) def test_setstate(self): # This checks whether __setstate__ does proper input validation. memio = self.ioclass() memio.__setstate__(("no error", "\n", 0, None)) memio.__setstate__(("no error", "", 0, {'spam': 3})) self.assertRaises(ValueError, memio.__setstate__, ("", "f", 0, None)) self.assertRaises(ValueError, memio.__setstate__, ("", "", -1, None)) self.assertRaises(TypeError, memio.__setstate__, (b"", "", 0, None)) self.assertRaises(TypeError, memio.__setstate__, ("", b"", 0, None)) self.assertRaises(TypeError, memio.__setstate__, ("", "", 0.0, None)) self.assertRaises(TypeError, memio.__setstate__, ("", "", 0, 0)) self.assertRaises(TypeError, memio.__setstate__, ("len-test", 0)) self.assertRaises(TypeError, memio.__setstate__) self.assertRaises(TypeError, memio.__setstate__, 0) memio.close() self.assertRaises(ValueError, memio.__setstate__, ("closed", "", 0, None)) class CStringIOPickleTest(PyStringIOPickleTest): UnsupportedOperation = io.UnsupportedOperation class ioclass(io.StringIO): def __new__(cls, *args, **kwargs): return pickle.loads(pickle.dumps(io.StringIO(*args, **kwargs))) def __init__(self, *args, **kwargs): pass def test_main(): tests = [PyBytesIOTest, PyStringIOTest, CBytesIOTest, CStringIOTest, PyStringIOPickleTest, CStringIOPickleTest] support.run_unittest(*tests) if __name__ == '__main__': test_main()