""" The purpose of this test file is to check how ctypes really work, down to what aliases what and what exact types operations return. """ import py from ctypes import * def test_primitive_pointer(): x = c_int(5) assert x.value == 5 x.value = 6 assert x.value == 6 p = pointer(x) # p ---> x = 6 assert isinstance(p.contents, c_int) p.contents.value += 1 assert x.value == 7 # p ---> x = 7 y = c_int(12) p.contents = y # p ---> y = 12 p.contents.value += 2 # p ---> y = 14 assert y.value == 14 assert x.value == 7 pp = pointer(p) # pp ---> p ---> y = 14 pp.contents.contents = x # pp ---> p ---> x = 7 p.contents.value += 2 # pp ---> p ---> x = 9 assert x.value == 9 assert isinstance(p[0], int) p[0] += 1 # pp ---> p ---> x = 10 assert x.value == 10 z = c_int(86) p[0] = z # pp ---> p ---> x = 86 (not z!) assert x.value == 86 z.value = 84 assert x.value == 86 assert isinstance(pp[0], POINTER(c_int)) assert pp[0].contents.value == x.value == 86 pp[0].contents = z # pp ---> p ---> z = 84 assert p.contents.value == z.value == 84 ## *** the rest is commented out because it should work but occasionally ## *** trigger a ctypes bug (SourceForge bug #1467852). *** ## q = pointer(y) ## pp[0] = q # pp ---> p ---> y = 14 ## assert y.value == 14 # (^^^ not q! ) ## assert p.contents.value == 14 ## assert pp.contents.contents.value == 14 ## q.contents = x ## assert pp.contents.contents.value == 14 def test_char_p(): x = c_char_p("hello\x00world") assert x.value == "hello" x.value = "world" assert x.value == "world" p = pointer(x) assert p[0] == x.value == "world" p[0] = "other" assert x.value == p.contents.value == p[0] == "other" myarray = (c_char_p * 10)() myarray[7] = "hello" assert isinstance(myarray[7], str) assert myarray[7] == "hello" def test_struct(): class tagpoint(Structure): _fields_ = [('x', c_int), ('p', POINTER(c_short))] y = c_short(123) z = c_short(-33) s = tagpoint() s.p.contents = z assert s.p.contents.value == -33 s.p = pointer(y) assert s.p.contents.value == 123 s.p.contents.value = 124 assert y.value == 124 s = tagpoint(x=12) assert s.x == 12 s = tagpoint(17, p=pointer(z)) assert s.x == 17 assert s.p.contents.value == -33 def test_void_p(): x = c_int(12) p1 = cast(pointer(x), c_void_p) p2 = cast(p1, POINTER(c_int)) assert p2.contents.value == 12 def test_char_array(): a = (c_char * 3)() a[0] = 'x' a[1] = 'y' assert a.value == 'xy' a[2] = 'z' assert a.value == 'xyz' b = create_string_buffer(3) assert type(b) is type(a) assert len(b) == 3 b.value = "nxw" assert b[0] == 'n' assert b[1] == 'x' assert b[2] == 'w' b.value = "?" assert b[0] == '?' assert b[1] == '\x00' assert b[2] == 'w' class S(Structure): _fields_ = [('p', POINTER(c_char))] s = S() s.p = b s.p.contents.value = '!' assert b.value == '!' assert len(create_string_buffer(0)) == 0 def test_array(): a = (c_int * 10)() class S(Structure): _fields_ = [('p', POINTER(c_int))] s = S() s.p = a s.p.contents.value = 42 assert a[0] == 42 a = (c_int * 5)(5, 6, 7) assert list(a) == [5, 6, 7, 0, 0] def test_truth_value(): p = POINTER(c_int)() assert not p p.contents = c_int(12) assert p # I can't figure out how to reset p to NULL... assert c_int(12) assert not c_int(0) # a bit strange, if you ask me assert c_int(-1) assert not c_byte(0) assert not c_char('\x00') # hum assert not c_float(0.0) assert not c_double(0.0) assert not c_ulonglong(0) assert c_ulonglong(2L**42) assert c_char_p("hello") assert c_char_p("") assert not c_char_p(None) assert not c_void_p() def test_py_object(): class TAG: pass x = py_object(TAG) assert x.value is TAG x.value = 42 assert x.value == 42 def test_pythonapi(): PyInt_AsLong = pythonapi.PyInt_AsLong PyInt_AsLong.argtypes = [py_object] PyInt_AsLong.restype = c_long assert PyInt_AsLong(py_object(17L)) == 17 py.test.raises(TypeError, "PyInt_AsLong(py_object('hello'))") def test_py_object_subclass(): PyInt_FromLong = pythonapi.PyInt_FromLong # automatic unwrapping of the py_object result PyInt_FromLong.argtypes = [c_long] PyInt_FromLong.restype = py_object assert isinstance(PyInt_FromLong(17), int) # but not if we subclass it... class W_Object(py_object): pass PyInt_FromLong.argtypes = [c_long] PyInt_FromLong.restype = W_Object assert isinstance(PyInt_FromLong(17), W_Object) def test_sizeof(): x = create_string_buffer(117) assert sizeof(x) == 117 # assumes that chars are one byte each x = (c_int * 42)() assert sizeof(x) == 42 * sizeof(c_int) def test_convert_pointers(): PyString_FromString = pythonapi.PyString_FromString PyString_FromString.restype = py_object # automatic conversions to c_char_p PyString_FromString.argtypes = [c_char_p] assert PyString_FromString("hello") == "hello" assert PyString_FromString(c_char_p("hello")) == "hello" assert PyString_FromString((c_char * 6)(*"hello")) == "hello" assert PyString_FromString(create_string_buffer("hello")) == "hello" # automatic conversions to c_void_p PyString_FromString.argtypes = [c_void_p] assert PyString_FromString("hello") == "hello" assert PyString_FromString(c_char_p("hello")) == "hello" assert PyString_FromString((c_char * 6)(*"hello")) == "hello" assert PyString_FromString((c_byte * 6)(104,101,108,108,111)) =="hello" assert PyString_FromString(create_string_buffer("hello")) == "hello" def test_varsize_cast(): import struct N = struct.calcsize("l") x = c_long() p = cast(pointer(x), POINTER(c_ubyte*N)) for i, c in enumerate(struct.pack("l", 12345678)): p.contents[i] = ord(c) assert x.value == 12345678 def test_cfunctype_inspection(): T = CFUNCTYPE(c_int, c_ubyte) # T.argtypes and T.restype don't work, must use a dummy instance assert list(T().argtypes) == [c_ubyte] assert T().restype == c_int